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Alex Obray English 84 cards

Cards in this deck (84)

  1. 11. What are the basic differences of X-rays and MRIs?High-energy x-rays easily pass through soft tissue like skin, lungs and muscles, but cannot penetrate dense objects like bones.
    MRIs are best suited for soft tissue e.g. ligaments. Low-energy radio waves, powerful magnets and a property of the nucleus help which all help to generate images of soft tissue.
  2. 22. Explain how hydrogen atoms help reveal the structure of soft tissue through MRIsSoft tissues comprises of many hydrogen atoms where the nucleus spins and wobbles in a cyclical fashion i.e. it "precesses" (or spins) like a tiny rotating top. The angle of the spin (or precession) is random.
    Radio waves are specifically "tuned" to the precession frequency of the hydrogen atom's nucleus. As hydrogen nuclei in the body absorbs this energy, they align and precess in the same direction. When the radio waves are turned off, they emit the absorbed energy in the form of radio waves where detectors collect this energy and use it to generate an image of soft tissue (e.g. brain)
  3. 33. What was the 1900 model of the atom?The atom consists of a sphere of positive charge with negative electrons dispersed inside it (like a chocolate chip cookie).
  4. 44. Explain Rutherford gold foil experiment and its implications.The experiment consisted of alpha particles passing through a thin shit of foil made of gold. Ernest Rutherfrod predicted all of the alpha particles would pass directly through. He observed that most of them did, however a few were widely deflected and even fewer were reflected back towards the source. He explain that the alpha particle must have hit a small object of dense positive charge.
    He discovered the nucleus where most of the atom consists of space with a dense positive core surrounded by orbiting electrons.
  5. 55. What is spectroscopy?The study of energy that is absorbed or emitted by matter. Each element of the periodic table emits its own characteristic spectrum of light when it absorbs energy.
    e.g. Hydrogen gas emits purplish light when electricity passes through it
  6. 66. What did Neil Bhor propose?That the distinct colours in line spectra were emitted by electrons. Electrons orbit the nucleus in at discrete energy levels where if they absorb energy (a photon) they "jump" from one level to another (electron transition). They will then spontaneously relax, emitting the excess energy and go back to a lower energy level. The energy emitted by the atom is the difference in energy between the two energy levels that the electron occupied.
  7. 77. What is way of producing x-rays by using a beam of electrons?First, bombard a suitable element with a beam of electrons, causing some of the inner orbit electrons to be knocked out of the atom, forming a temporary "hole." The resulting electron hole can be filled by an electron in the atom's intermediate or outer orbits. If the electron comes from an outer orbit, it will emit a high-energy x-ray.
  8. 88. Explain why atomic emission spectra are sometimes called "fingerprints".Each element has a unique atomic emission spectrum similar to the way that each person has a unique fingerprint.
  9. 99. In terms of quantum mechanics, what are orbitals?The region of space around the nucleus in which the probability of finding the electron is high. (these are high probability regions or electron clouds)
  10. 1010. Explain electron density, the outer boundary and the area within the orbitalThe electron density is greatest at the centre of the orbital (the nucleus) and decreases as the distance from the nucleus increases.
    Theoretically there is no outer limit on where the electron can be away from the nucleus but for practical purpose, each orbital has an outer boundary.
    The area within the orbital represents the region around the nucleus in which the probability of finding the electron is about 95%.
  11. 1112. What does the shape and energy or orbitals depend on?By solutions to the Schrodinger wave equation.
  12. 1213. What forms the shape of an atom?Since an atomic orbital is like a three-dimensional wave, the shape of an atom is the result of the blending of its orbitals (since they interfere constructively, similar to pulses, but they will stay together, unlike passing water waves)
  13. 1314. What is the energy-level diagram?Under normal condition, the relative energies of the orbitals
  14. 1415. Why is it useful to compare the enregies of the orbitals and the number of electrons they occupy?Useful for predicting the properties of the elements in the periodic table.
  15. 1516. What happens when you proceed to higher energy levels?The distance between energy levels decreases
  16. 1617. Explain the spin of electrons.Experimental evidence suggest electrons spin and that there are two possible spin states (represented by up and down arrows). If there is only one e- in the orbital, the spin state of the e- can either be up or down. If there is a second. If the obital contains two electrons, they must have opposite spins. If the second e- has the same spin, it will not be able to occupy the same energy level. This is known as the Pauli Exclusion Principle
  17. 1718. Explain the Pauli Exclusion Principlea
  18. 1819. What have chemists found when two electrons have opposite spins?The electron repulsion is minimized.
  19. 1920. What is the Aufbau Principle ("Lowest fill first")?The lowest energy levels of the orbitals are filled first.
  20. 2021. What is Hun's Rule ("Align Spins")When e-s are placed within a sub-level of orbitals with identical energy (p, d, or f), electron repulsion is minimized if each orbital receives one e- (in the same direction) before pairing occurs
  21. 2122. How do the words "orbit" and "orbital" differ?"Orbit" describe the path of an electron around the nucleus of an atom in the Bohr model. This is analogous to planetary orbits. The term "Orbital" is used in the quantum mechanical model of the atoms, representing the probability region around the nucleus in which the probability of finding the electron is high.
  22. 2223. What is the electronic configuration?Used to convey the electron arrangements of the elements. It gives the correct order of orbitals from lowest to highest energy as well as the number of electrons that occupy each orbital
  23. 2324. What does isoelectronic mean?Having the same number of electrons
  24. 2425. What is a consequence of atoms of elements gaining or losing electrons?They tend to gain or lose electrons so they have the same electron arrangements as their nearest noble gas.
  25. 2526. Explain which ions selenium, Se (Z = 34) and strontium, Sr (Z=38) will more likely formSe2-, so Selenium will gain two electrons in order to be isoelectronic with its nearest noble gas, krypton (Z = 36). For strontium, it will more likely form Sr2+ since krpyton has two less electrons than Sr, so it needs to lose 2 electrons, to form a cation in order to share the same electron arrangement as its nearest noble gas.
  26. 2627. The emission spectrum of an unknown element contains two lines - one in the visible portion of the spectrum, and the other, ultraviolet. Based on the electromagnetic spectrum and what you know about Niels Bohr's model of the atom, account for the difference in energy between these lines.Bohr suggested that the distinct colours in the line spectra were emitted by electrons. Electrons orbit the nucleus in discrete orbits, corresponding to discrete energies. When electrons absorb energy, they jump to a higher energy level. They will then undergo spontaneous relaxation, emitting the excess energy and jumping back down. The amount of energy emitted is equal the difference between the two energy levels the electron occupies. The spectral line found in the ultraviolet part of the spectrum is more energetic than visible light waveband, so the energy difference for the transition which emitted ultraviolet radiation must be larger.
  27. 2728. Compare the stability of the Zr atom and Zr ion (Zr4+)The Zr4+ ion is more stable because its valence shell is filled, meaning it will seldom interact. This has the same electron arrangement as krypton which is a noble has where noble gases very rarely interact since they are very stable. On the other hand, Zr does not possess a full valence shell so it will be more reactive and less stable as a consequence.
  28. 2829. Explain why hydrogen is diatomic in nature.The hydrogen molecule forms because the electrostatic attractions between the proton of one atom for the electron is greater than the proton-proton and electron-electron repulsions.
  29. 2930. Explain what occurs when two hydrogen atoms approach each other.The proton begins to exert an attraction for the electron of the other atoms, causing the atoms to move closer together, decreasing potential energy of the system.
  30. 3031. What occurs if the collision of two hydrogen atoms is "just right"?The attractive and repulsive forces equal each other, so the nuclei reaches a stable point. The atoms share the pair of electrons (since they're both attracted to both nuclei), resulting in a filled valence shell (stable)
  31. 3132. What is the stable distance between two hydrogen atoms?The average bond length for the hydrogen molecule.
  32. 3233. What is the energy released from the system equal to when a hydrogen molecule forms from its atoms?Equal to the difference in energy between the initial and the minimum potential energy state.
  33. 3334. What is a covalent bond?Sharing electrons between atoms
  34. 3435. What generally occurs from the formation of any chemical bond? What about if atoms are forced together, closer than the average bond length?A decrease of potential energy
    The electron-electron and proton-proton repulsions exceed the attractive forces and potential energy increases
  35. 3536. When a covalent bond forms from the formation of a hydrogen molecule, what occurs to the orbitals?The orbitals overlap (The 1s orbitals in this case_). Once this occurs, the shared electron pair can travel throughout the entire molecule
  36. 3637. What are the four fundamental ideas of Lewis structures1. The noble gases (group 18) are stable because they have filled outer/valence orbits e.g. all noble gases have eight electrons (apart from helium)
    2. Atoms gain, lose or share electrons to achieve an electron arrangement like that of the nearest noble gas, completing their octet. e.g. magneium reacts to lose two valence e-s -> mg2+ ion (stable)
    3. Metal atoms tend to lose e's to achieve stability
    4. non-metal tend to gain electrons AS WELL as share to achieve stability
  37. 3738. What's the difference between paired and single electrons in electron dot diagrams?Atoms share their single electrons with other atoms to form covalent bonds. Pair electrons, which are called lone pairs, rarely participate in bonding.
  38. 3839. It was thought that carbon would interact with two hydrogen atoms to form CH2 however, this is unstable and instead, it will more likely form CH4. Experimental evidence suggests the carbon atom is surrounded by all four hydrogen atoms and that the four covalent bonds of the central carbon atom are the same in strength and in length. This can only be possible if:This can only be possible if the four orbitals that carbon uses for bonding are identical.
  39. 3940. Using orbital hybridization, explain how carbon produces four identical bonds by having four identical orbitsThe orbitals for carbon is that 1s is filled (2 e-s), 2s is filled (2 e-s) and 2p (which can occupy 6 e's) contains 2 electrons. One of the electrons from 2s presumably absorbs energy from the environment and and moves to the empty 2p orbital (possible since the energy difference between 2s and 2p is small). However, three of the bonds use p orbitals and the fourth involves 2s. What happens is that the 2s and 2p orbitals of carbon blend together to form four new identical orbitals called sp^3 hybrid orbitals (1 s orbital and 3 p orbitals)
  40. 4041. What is a crucial note about hybridization, why does it exist and is it a natural process?Orbital hybridization is a theoretical alteration to bonding theory. The alteration (hybridization) exists so that the theory can agree with what is observed in nature.
    It is not a natural process that can be observed and measured.
  41. 4142. It is expected that boron would only form one bond (according to its energy-level diagram) since it only has one e electron in the 2p orbital. However, BH exists, however it is extremely reactive while BH3 is more stable. Experimental evidence shows that the three bonds in BH3 are identical. Explain how this is possible through hybridization.An electron in the 2s orbital is promoted to the 2p orbital, moving to an empty 2p orbital. The 2p orbital (now containg 2 electrons) and the 2s orbital (containing ) blend together (hybridize) to form three identical hybrid orbitals called sp^2 hybrid orbitals.
    However, unlike methane, CH4, boron trihydride, Bh3 is quite reactive. This is caused by the empty p orbital. Bh3 readily reacts with another entity that has a lone pair of electrons that can be inserted into the empty 2p orbital. (e.g. Bh3 readily reacts with the hydride ion, H- to produce BH4-)
  42. 4243. Describe why the concept of orbital hybridization is necessary to explain the bonding in carbonThe concept of orbital hybridization for explaining bonding in carbon is necessary for justifying why most carbon compounds form four identical bonds. Without hybrid orbitals, bonding theory predicts that carbon forms only two bonds, using two 2p orbitals.
  43. 4344. What is a polar covalent bond? What does a polar covalent bond result in? Give an exampleElectrons being shared unequally
    They result in a partial charge separation e.g. for hydrogen chloride, HCl, the chlorine end of the molecule is slightly negative and the hydrogen end is slightly positive.
  44. 4445. What is electronegativity?The measure of an atoms ability to attract a shared pair of electrons (attract electrons in a chemical bond)
  45. 4546. What occurs when the bond between two elements is extremely polar? What type of bond is this called?No electron sharing occurs at all. The electron is completely transferred from the elecrtopositive element to the electronegative element, becoming a cation and anion, respectively. These ions are bonded to each other as a result of the positive-negative (or electrostatic) attraction between them.
    These are known as ionic bonds
  46. 4647. What is the "rule of thumb" separation between polar covalent bonds and ionic bonds?1.7
  47. 4748. What is Valence Shell Electron Pair Repulsion (VSEPR) theory? What is it based on?To explain and predict molecular shape
    It is based on the observation that negative charges of electrons inside an atom repel each other. As a consequence, the orbitals that the electrons occupy try to get as far away from one another as possible.
    Therefore, the bond angles (or the angles at which other atoms connect to) the central atom are determined by the orientation of these electron pairs.
  48. 4849. What is a bond angle?The angle that the bonds make with each other.
  49. 4950. Explain why the boron atom in BF3 has lost its three outer electrons. Determine the shape of the molecule.Remember, atoms tend to gain or lose electrons to be isoelectronic (same electron arrangements) as their nearest gas. Boron has five electrons: 3 valence e's and two inner e's. It will tend to lose 3 than gain 5 (thereby achieving a stable octet). The boron atom in BF3 has lost its three outer electrons to achieve the noble gas electronic configuration of helium. boron is surrounded by three bond pairs and no lone pairs. This molecule is a trigonal planar.
  50. 5051. What is a dipole?The unequal distribution of charge between bonding atoms
  51. 5152. When do substances typically dissolve in each other?When they are substances of similar polarity (.e.g. CO2, oil, fats)
  52. 5253. the molecular shapes of water and methane are based on Sp3 hybrid orbitals attached to the central atoms. Why are the bond angles in these molecules not identical?Methane forms a tetrahedron with sp^3 hybridization orbitals with four hydrogen atoms around the central carbon atom with no lone pairs. This forms bond angles of 109.5 degrees due to the symmetrical nature of the molecule. The water molecule contains sp3 hybridization where the central oxygen has two bonds but also a lone pair. This lone pair distorts the tetrahedral bond angle since the bond angles of the central atom depends on the orientation of the lone pairs. This gives a bond angle of 104.5 degrees.
  53. 5354. Why us carbon dioxide a suitable solvent to use?Carbon dioxide is a suitable solvent since it is a substance of similar polarity to oil and grease. Remember that substances with similar polarity typically dissolve. Carbon dioxide is a non-polar molecule just like oil and grease, which is the reason why liquid carbon dioxide can lift oil and grease off fabrics.
  54. 5455. What is molecular mass (and molecular mass)? What is the molecular mass of H2O?the mass of a given substance divided by the amount of substance
    16 + 1 + 1 = 18
  55. 5556. What is a dipole-dipole attraction?Dipole-dipole forces are caused by positive and negative ends of a molecule which attract each other like little magnets (despite hydrogen chloride being a neutral molecule, the unequal distribution of electrons in the molecule produces a charge separation called a dipole )
    If a positive end comes close enough to a negative end, they form a dipole-dipole attraction.
  56. 5657. What type of molecules have the ability to form dipole-dipole attractions between molecules?Only polar covalent molecules
  57. 5758. How strong is a dipole-dipole attraction compared to a covalent bond?weak - 1/100 the strength of a covalent bond
  58. 5858. What happens when you cool substances under pressure?They eventually condense into solids and liquids
  59. 5959. What are london forces? Explain an example of london forces between two hydrogen molecules (H2)They result from the movement of the electrons in the molecule which generates temporary positive and negative regions in the molecule.
    At any given moment, a temporary unequal distribution of electrons can occur, creating a temporary dipole in the first molecule (A). The presence of this dipole repels the electrons in nearby molecule B, inducing a temporary dipole in molecule B. A weak electrostatic attraction forms between the two atoms, called a london force.
  60. 6060. Why do larger non-polar substances have higher melting and boiling points in comparison to smaller substances of similar shape?As the size of the molecule increases, there are more places between the molecule where london forces can form.
  61. 6161. When there is no other intermolecular attraction, what do the london forces determine?They determine many of the physical properties of elements and molecular substances.
  62. 6262. If water followed the trend of group 16's hydrogen compounds (where the boiling point increases as you advance to larger elements within the group), what would its boiling point be and what would the implication be for us? Why does the boiling point of water not follow this trend?-50 degrees Celsius, so it would be vapor at room temperature. Therefore the water in our bodies would instantly boil.
    Because water has more than one type of intermolecular attraction between molecules (london forces) known as hydrogen bonding
  63. 6363. Explain hydrogen bondingThe electronegativity difference between hydrogen and oxygen is large, therefore the hydrogen-to-oxygen bond in the water molecule is very polar where the electrons that make up the bond spend more time around the oxygen atom, forming partial charges. Remember most hydrogen atom consists of 1 proton and 1 electron (neutral hydrogen). If the electron is pulled away for much of the time, the proton of the hydrogen atom is exposed. Since protons are extremely small, their positive charge is concentrated into a small volume. As a result, the hydrogen proton forms strong attractions for the lone pair of electrons on the δ- side of the oxygen atom of a neighbouring water molecule.
  64. 6464. How much stronger hydrogen bonds in comparison to dipole-dipole bonds?10 times
  65. 6565. What kind of elements form hydrogen bonding? What is required in order to form a hydrogen bond?The most electronegative elements - nitrogen, oxygen and fluorine.
    A hydrogen atom must be attached to one of these three elements in one molecule.
    The hydrogen atom would then attract an N, O, or F atom on a nearby molecule (since these molecules are highly polarized)
  66. 6666. What is hydrogen bonding responsible for?DNA and proteins.
  67. 6767. What is surface tension? What increases and decreases surface tension?The energy required to increase the surface area of a liquid by a fixed amount. The molecules are the surface are experiencing a force that holds it down to the surface. Molecules and liquids minimize their energy by minimizing surface area. Surface tension increase with increasing interaction energy or intermolecular forces, and decreases with increasing thermal energy or temperature.
  68. 6868. Predict which of the following pairs or molecules have the stronger intermolecular forms of attraction. Justify your prediction a) Hydrogen fluoride (HF to HF), or fluorine, (F2 to F2) b) Phosphorus trihydride, (PH3 to PH3), or ammonia, (NH3, to NH3) c) hydrogen fluoride, (HF to HF), or hydrogen chloride, (HCl to HCl)a) HF has the strongest attractions because it consists of polar molecules held together by hydrogen bonding. F3 consists of non-polar molecules held together by weak london forces. Hydrogen bonding occurs with the most electronegative elements of the periodic table - nitrogen, oxygen and fluorine.
    b) NH3 has the strongest attractions. PH3 and NH3 are both polar molecules. NH3 has hydrogen bonding because nitrogen is a highly electronegative element. PH3 contains only dipole-dipole attractions that are weaker than hydrogen bonds.
    c) HF has stronger attractions because it contains hydrogen bonds, while HCl contains only dipole-dipole attractions. Again, hydrogen bondning occurs with the most electronegative elements of the periodic table - nitrogen, oxygen, and fluorine.
  69. 6969. Use the concept of hydrogen bonding to explain which would hurt more: a belly-flop dive into a pool of water, or one into a pol of oil. (Hint: most of the molecules in oil are non-polar)A belly flop into the pool of water hurts more because its hydrogen bonds cause the surface tension of the water to be stronger than the surface tension of the oil. The higher surface tension is a result of hydrogen bonding in water. Oil has some surface tension because it is weaker in comparison. Because oils consists of non-polar molecules, its attractive forces are London forces, which are weaker than hydrogen bonds.
  70. 7070. List some basic characteristics of solids What do the properties of solids depend on?They have a definite shape and volume and are difficult to compress (compared to liquids and gases).
    They depend on what particles the solid consists of and the attractive forces between these particles
  71. 7171. List some properties of an ionic solidThey are hard, brittle substances with high melting points. They are soluble in water, producing solutions that conduct electricity.
    Ionic solids do not conduct electricity in the solid state, but do they do when they are melted into liquid form
  72. 7272. Analyzing sodium chloride, which is an ionic solid, explain its crystalline structure and the ratio of cations to anions.The crystalline structures involves an alternating pattern of cations and anions.
    The ratio of cations to anions in the crystal is given by the chemical formula of the compound - NaCl, so 1 sodium atom for every chlorine atom.
  73. 7373. What holds ionic solids together? What makes an ionic solid hard and have a high melting point? What makes an ionic solid brittle? Why do ionic solids not conduct electricity but do in the liquid state?The electrostatic attraction between cations and anions keeps ionic solids together, called ionics bonds.
    The hardness and high melting point is due to the high strength of the ionic bond
    ionic solids are brittle, because strong ionic bonds prevent one layer of the crystal from sliding past another, when pushed.
    They don't conduct electricity in a solid state because its ions are locked in position, but when dissolved (in saline solution for NaCl) its ions are free to move so ionic liquids conduct electricity (ions carry electric charges and move freely)
  74. 7474. What are some general characteristics of metallic solids (or metals)? What general characterists can vary for metals?Shiny flexible solids that are excellent conductors of heat and electricity.
    The have low ionize energies (energy required to remove an outermost or electron or valence e-) and have many empty orbitals
    The hardness of metals vary considerable (e.g. group 1 - alkaline metals are soft and can be cut easily while iron is quite hard).
    The melting points of metallic solids vary considerably. e.g. mecury is a liquid at room temperature, tungstens melting point is over 2000°C
  75. 7575. Explain the trend of ionization energy for metals. What do the empty orbitals of metals allow? Explain what experimental evidence suggests for the structure of a metalMetals located on the far left of the periodic table have low ionization energies and will lose their valence electrons readily.
    The availability of empty orbitals allows metal to conduct electricity well.
    Experimental evidence suggests that metallic solids don't contain "separate atoms" at all. Rather, a typical metal consists of an array of positive ions surrounded by a "fluid" of outer orbital electrons. This "fluid" is often described as a "delocalized (electrons are not attached to a particular atom) sea (the outer orbital electrons can flow easily through the metal" of electrons.
  76. 7676. What main attraction is formed in metallic solids? What is a simple analogy to help understand the metallic bond?The attraction between the metal ion and the electrons is called the metallic bond.
    TA useful model to help understand the metallic bond is a rice krispies square Electrons are represented by the "marshmallow glue" that holds the puffed rice together. The metal ions in the solid represent each grain of puffed rice. Like most metals, these cereal squares are flexible and can be bent or squashed without snapping in two.
  77. 7777. Why are metals flexible? Why are metals good conductors of electricty?Because there isn't a rigid bond between one layer of cations and the next. Therefore, one layer can slide past the other easily when a piece of metal is bent or hammered.
    Because electrons are not strongly attracted to one particular atom. Instead, they can readily flow through a metal.2
  78. 7878. What are covalent network solids? What are some general characteristics and what can they be explain by?Covalent network solids consists of numerous atoms connected together by covalent bonds E.g. a daimond (C) and quartz (SiO2).
    They are hard, brittle and generally poor conductors of electricity. They also have extremely high melting points.
  79. 7979. Explain what causes the general characteristics of a covalent network solidMost of their properties can be explained by the bonding with the substances.
    Hardness, brittleness and a high melting point are a direct result of the strong covalent bonds between atoms in the substances.
    Because the electrons in these substances are localized or stuck within covalent bonds, covalent network solids are poor conductors of electricty.
  80. 8080. Compare graphite to carbon. What covalent network solid has been created from this? What industry benefits from this material?Graphite, like carbon, consists of carbon atoms, however, they are arranged in two-dimensional sheets. Each sheet consists of carbon atoms arranged in cells, in the shape of a hexagon, with covalent bonds between the atoms (like carbon). However, they bonds between sheets are london forces.
    A new covalent network solid involving hexagonal cells of carbon has been developed, known as carbon nanotubes. Unlike graphite, they have no edges. There the carbon atoms within the substance forms a continuous tube of covalently linked carbon atoms. They are several times stronger than steel and are very light. They are ideal for building material for the aerospace industry.
  81. 8181. What do molecular solids consists of? What are some characteristic properties and what are they caused by? What is an exception to some of these properties?elements like sulfur, or molecules like water or carbon ioxide.
    The substances are held together by hydrogen bonding, dipole-dipole attractions, or london forces. Since these attractions are weak, they are generally soft, are poor conductors of electricity (electrons are localized in the covalent bonds within each molecule. They also don't release ions so don't conduct electricity in solution) and have low melting points.
    Molecular acids release ions when they are added to water. They produce solutions that can conduct electrify unlike pure water by itself (poor conductors of electricity)
  82. 8282. Explain why calcium fluoride conducts electricity only when it is melted or dissolved in water.Calcium fluoride cannot conduct electricity in a solid state since the ions are held in potion. If the compound dissolves or melts, it can conduct electricity since the ions can move freely (separated from the crystal(
  83. 8383. Silicon dioxide, SiO2, and carbon dioxide, CO2, have similar chemical formulas, but different physical properties. Why is silicon dioxide a hard solid at room temperature, while carbon dioxide is a gas at room temperature?Since carbon dioxide is a non-polar molecule (due to the symmetrical nature around the central atom), it is held together in the solid state by London forces (the attractive forces between CO2 molecules). These intermolecular attractions are the weakest of all forms of intermolecular bonding. Consequently, solid carbon dioxide readily changes into a gas at room temperature.
    Silicon dioxide (SO2), however, is a network solid, in which silicon and oxygen atoms are covalently bonded. Since these attractions are so strong, silicon dioxide is a solid at room temperautre.
  84. 84—

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Flashcards on Untitled, created by Alex Obray on 05/06/2016.
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Alex Obray · Jun 2016
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