4531195
Description
Flashcards by Kayla Price, updated more than 1 year ago
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Created by Kayla Price
about 8 years ago
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| Question | Answer |
| What happens to the ionisation energy of a species when an electron is being removed from a new inner shell? | It decreases dramatically because not only is there a greater effective nuclear charge but there is also less shielding from inner electron shells. This increases the electron's attraction to the positive nucleus and makes it more difficult to remove |
| What happens to the atomic radii of elements across a period? | Atomic radii decreases because the number of protons increases, so the effective nuclear charge increases. The stronger nuclear attraction on the electrons means they get pulled in closer, hence atomic radius decreases. |
| What happens to the atomic radii of elements down a group? | Atomic radii increase because there is an increase in electrons, so increase shielding due to and increase in energy levels. This means there is less nuclear attraction on the outer electrons so they are not held in as closely. |
| What happens to first ionisation energies across periods 2 and 3? | They increase because across the periods there are more protons in the nucleus and hence grater nuclear charge and therefore the outer electron is more firmly held. There are some dips during this trend when the outer electron is alone in it's outer shell so it is easier to remove. |
| What happens to first ionisation energies down a group? | They decrease because down a group, there are more electrons and so more energy levels which means more shielding. The outer electrons are therefore less attracted to the nucleus and so are less attracted to the nucleus. |
| Define electronegativity | The ability for the nucleus of an atom to attract a pair of electrons in a covalent bond |
| Describe the process you would use to prove quantum energy levels | The atomic emission spectra of elements. A species is heated, which gives it energy. Electrons have the ability to move to a higher energy level because of the energy provided by the heat. When they do this they are in an excited state. When the electron drops back down (to ground state), the same amount of energy absorbed by the electron is released in the form of light. The different colours produced by different frequencies of light are specific to different types of species and show that there are quantum energy levels. |
| What is ionic bonding? | The strong electrostatic attraction between oppositely charged ions. |
| How many electrons can s subshells hold? | 2 |
| How many electrons can p subshells hold? | 6 |
| How many electrons can d subshells hold? | 10 |
| Why is RAM not an exact whole number? | Most elements have naturally occurring isotopes which are taken into account when finding a relative atomic mass. The isotopes' abundance is also taken into account so the RAM is around the most commonly occurring isotope. The will usually make the RAM not an exact whole number. |
| Describe the process of mass spectrometry | 1) All the air in the spectrometer is pumped out 2) A gaseous sample sample of an element or compound and is bombarded with high energy electrons from an electron. 3) The energy from the bombarding electrons strips electrons from the atoms or molecules, forming positive ions ( A(g) + energy --> A+(g) + e- ) 4) The positive ions are accelerated by the high electric potential, pass through slits and emerge as a beam of ions. 5) Ions are deflected by a powerful magnetic field. Ions with a greater mass are deflected less than those with a smaller mass. 6) Ions are detected and a computer calculates the relative abundance of each mass detected. |
| What is the molecular ion peak? | The peak on the far right on the spectra which corresponds to the molecular mass of the molecule. |
| What is the base peak? | The peak which shows the most abundance |
| What is the maximum number of electrons that can fill each energy level? | n=1 2 n=2 8 n=3 18 n=4 32 |
| What are orbitals? | A region of space in a subshell where an electron is found. Each orbital can only hold a max of 2 electrons and this only happens if there are no other free orbitals. |
| What is the Heisenberg uncertainty principle? | It's impossible to define with absolute precision, at the same time, both the precision and momentum of an electron. |
| What is the shape of an s-orbital? | Spherical |
| What is the shape of a p-orbital? | |
| What is the shape of a d-orbital? | |
| What is Hund's rule? | When electrons are placed in orbitals with equal energy, they spread out to maximize the number of unpaired electrons. |
| What is the Aufbau principle? | Electrons in an atom start in the lowest energy orbital, as they are added they occupy the lowest energy orbital available |
| Define first ionisation energy? | The first ionisation of an element is the energy required to remove 1 electron from 1 mole of gaseous atoms of that element. |
| Why do the successive ionisation energies for an atom increase? | Each electron gets harder to remove due to a greater number of positive protons in the nucleus compared to negative electrons surrounding it (higher proton to electron ratio). This positive charge in the nucleus is the effective nuclear charge, which increases. This causes electrons to be pulled in closer and held more tightly, making them harder to remove. |
| Define covalent bonding? | The strong electrostatic attraction between the positive nuclei and their shared electrons |
| What are the bond angles of a trigonal planar? | 120 |
| What are the bond angles of a tetrahedral? | 109.5 |
| What are the bond angles of a trigonal bipyramid? | 90, 120 and 180 |
| What are the bond angles of an octahedral? | 90 and 180 |
| How would you find the number of lone pairs in a molecule? | (group no. - no. of bonds) / 2 |
| What is bond length? | The distance between nuclei of atoms that are covalently bonded to eachother |
| Describe a pure ionic bond | There is no overlapping of electron density between ionically bonded atoms because difference in electronegativity is not large enough |
| Describe a covalent bond with ionic character | There is an uneven distribution of electron density in the bond because of a large difference in electronegativity |
| Describe an ionic bond with covalent character | Electron density is pulled towards a highly electronegative atom in the bond, forming an egg like shape of the less electronegative atom |
| What happens to electronegativity down a group | Decreases because of an increase in shielding |
| What happens to electronegativity as you go across a period? | Increases because there is no overall increase in shielding and an increase in effective nuclear charge |
| Why do linear molecules have a high boiling point? | They can pack close together so london forces are stronger |
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