Flashcards
Topic 1 - Atomic structure and the periodic table
Cards in this deck (22)
- 1What are the four basic facts about atoms?1. atoms contain protons, neutrons and electrons.
2. number of protons = number of electrons (therefore its neutral unlike ions).
3. atomic mass (num of protons+nuetrons) and atomic number (num of protons ) describes an atom.
4. atoms can be represented by symbols. - 2What is an element?Elements are groups of atoms with the same atomic number.
- 3What is an isotope?Different forms of the same element, which have the same number of protons but a different number of neutrons.
- 4When referring to an element as a whole how do you use the relative atomic mass and formula?Relative atomic mass is an average mass taking into account. the different masses and abundances (amounts) of all the isotopes that make up the element. Relative atomic mass = sum of (isotope abundance*isotope mass / sum of all the isotopes.
- 5Explain how ionic compound forms?Between a metal and non-metal. Metal atom loses electrons to become a positively charged ion. Non-metal gains these electrons to form a negatively charged ion. The opposite charges mean the two ions are strongly attracted to each other and form a compound e.g. NaCl, MgO, CaO.
- 6Explain how a covalent bond forms?Between two non-metals. Each atom shares an electron with the other e.g. HCl, CO, H2O.
- 7Name all the common formulas?CO2,NaCl,NH3,CO,H2O,HCl, CaCl2-calcium chloride, Na2CO3-sodium carbonate,H2SO4-sulfuric acid.
- 8What are the two main ways of separating soluble solids from solutions?1. evaporation - 1. pour solution into an evaporation dish. 2. slowly heat the solution, the solution will evaporate and the solution will get more concentrated. Eventually crystals will start to form.
3. Keep heating and eventually all you will have left are dry crystals.
1. crystallisation - 1. pour solution into an evaporation dish and heat. 2. as crystals start to form (point of crystallisation), leave to cool. 3. the salt should form crystals as it becomes insoluble in the cold, highly concentrated solution. 4. filter the crystals out of the solution and leave to dry. - 9Explain simple distillation?Used for separating a liquid from a solution. Solution is heated and parts of it that have the lowest BP will evaporate first. The vapour is then cooled and condensed into a liquid. This then is collected, however BPs have to be very different.
- 10Explain fractional distillation?1. Put a mixture of liquids in a flask with a fractionating column on top, then heat.
2. The different liquids will all have different BPs so will evaporate at different temps.
3. The liquid with the lowest BP will evaporate first. The when the temp on the thermometer matches the boiling point of the liquid it will reach the top of the column.
4. Liquids with higher BPs might also start to evaporate, but the column has a temp gradient so they will not reach the top before condensing.
5. When the first liquid is collected, you can raise the temp until the next liquid reaches the top. Each liquid collected is called a fraction. - 11What is the certain number of electrons in each cell?2,8,8,2
- 12How does the electron structure of an atom affect how it will react?Atoms usually react to form a full outer shell. Metals to the left, don't have many electrons in their outer shell to remove to gain a full outer shell, also metals to the bottom have their outer electrons further away from the nucleus so feel a weaker force of attraction between the negative electrons and positive nucleus. Both of these affects mean not much energy needed to remove the electrons from the outer shell so they form positive ions. For non-metals, the ones on the right have lots of electrons in their outer shells so its easier to gain few than lose loads. At the top the electrons are closer to the nucleus so stronger force of attraction so form negative ions.
- 13Describe the trends in groups 2 and 3 (the transition metals)?Metal properties, can have more than one ion. Cu2+, colourful compounds, good catalysts.
- 14Describe the trends in group 1 (alkali metals)?Soft, low density, increased reactivity as you go down, lower BP and MP as you go down, form ionic compounds with non-metals.
- 15What happens when you react an alkali metal in water?Reacts vigorously to produce hydrogen gas and metal hydroxides (salts that dissolve in water to produce an alkali solution).
- 16What happens when you react an alkali metal in chlorine?Reacts vigorously when heated in chlorine to form white metal chlorine salts.
- 17What happens when you react an alkali metal in oxygen?Reacts to form metal oxides. (dulling when sliced)
- 18Describe the trends in group 7 (halogens)?They are all non-metals with coloured vapours. They all exist as pairs of atoms. Less reactive as you go down. Higher BP and MP as you go down. Covalent bonding with other non-metals, ionic with metals to form halides (F-,Cl-,Br-,I-). More reactive halogens will displace less reactive ones.
- 19What are the properties of each halogen?fluorine - very reactive, poisonous, yellow gas.
chlorine - fairly reactive, poisonous, dense, green gas.
bromine - dense, poisonous, red/brown, volatile liquid.
iodine - dark grey, crystalline solid purple vapour. - 20Describe the trends in group 0 (noble gases)?All have full outer shell, unreactive/inert, monatomic, colourless at room temp, non-flammable, BP and MP increases as you go down - increased number of electrons meaning greater inter molecular force which needs to be overcome.
- 21Explain how to do paper chromatography?1. draw a pencil (insoluble) line near the bottom of a sheet of filter paper.
2. add a spot of ink to the line and place the sheet in a beaker of solvent (water).
3. the solvent used depends on what is being tested as some compounds will dissolve in water but sometimes other solvents like ethanol are needed, make sure the solvent isn't touching the ink.
4. place a lid on the container to stop the solvent evaporating.
6. the solvent will seep up the paper, carrying ink with it.
7. each dye will move up the paper at different rates so the dyes will separate. Each dye will form a spot in a different place.
8. if any of the dyes in the ink are insoluble they will stay at the line.
9. when the solvent has nearly reached the top of the paper, take the paper out of the beaker and leave to dry, end product is a chromatogram. - 22How do you use filtration and crystallisation to separate rock salt?1. grinding
2. dissolving
3. filtering
4. evaporation
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- Year 11 Chemistry Flashcards on Topic 1 - Atomic structure and the periodic table, created by finn squires on 12/12/2017.
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