Topic 1 Flashcards

Question

Simple Distillation

Answer 1

- used to separate out solutions 1) simple distillation is used for separating out a liquid from a solution 2) solution is heated, part of solution with lowest boiling point evaporates first 3) vapour is than cooled, condenses and collected 4) rest of solution is left behind in the flask 5) you can use simple distillation to get pure water from seawater. Water evaporates and is condensed and collected, eventually you will end up with just salt left in flask

Answer 2

To separate a mixture of liquids 1) put your mixture in a flask and stick a fractionating column on top, than heat it 2) diff liquids have diff boiling points so will evaporate at diff temperatures 3) liquid with lowest boiling point will evaporate first, when thermometer matches boiling point it will reach the top of the column 4) higher boiling points will evaporate but will only get half the way up of the column before condensing and running back down the column 5) when first liquid has been collected you raise the temperature until the next one reaches the top

Answer 3

1) 19th century John Dalton described atoms as solid spheres, and said that different spheres made up different elements 2) 1887 J J Thomson concluded from his experiments that atoms weren't solid spheres and the atom contained electrons, and this was called the 'plum pudding model' 3) the plum pudding model shows the atom as a ball of positive charge with electrons stuck in it

Answer 4

In 1909 Ernest Rutherford and Ernest Marsden conducted the alpha particle scattering experiments, they fired charged alpha particles at an extremely thin sheet of gold. Most passed through but some were deflected back. This was made to be the nuclear model, this has a tiny positive charged nucleus at the center where most of the mass was concentrated at, and the rest of the atom was empty space.

Answer 5

He suggested all the electrons contained in shell and orbit the nucleus in fixed shells

Answer 6

Discovered neutrons

Answer 7

- lowest energy levels are the ones closest to the nucleus and always filled first - only a certain number of electrons are allowed in each shell: 1st shell is 2, 2nd shell is 8 and 3rd shell is 8 - atoms wants a full outer shell - in most atoms the outer shell is not full and this makes the atom want to react to fill it

Answer 8

They were arranged by atomic mass, and categorised in the physical and chemical properties and their relative atomic mass.

Answer 9

-he put the elements in order of atomic mass -he switched order if properties meant needed to be changed Example: he switched Te and I, Iodine has a smaller mass but placed after tellurium as it had similar properties to the elements in that group. Example: he left gaps in the table for elements that were not discovered yet, these were ekasilicon and germanium

Answer 10

- 100 ish elements - elements are ordered in increasing atomic number - metals are found on the left - non-metals are found on the right - elements with similar properties form columns and these vertical columns are called groups - group number tells you how many electrons are in the outer shell apart from helium in group 0 - if you know properties of one element you can predict properties of elements in that group and predict trends as you go down the group - rows are called periods and each new period represents another full shell of electrons

Answer 11

- most elements are metals - they are towards the bottom and to the left of the periodic table - involve metallic bonding - strong - malleable - good conductor of electricity and heat - high boiling and melting points

Answer 12

- far from the right and top of the periodic table - harder for them to form positive ions as they have more electrons - low density - brittle - don't conduct electricity or heat

Answer 13

- alkali metals - one electron on outer shell - soft and low density - increases activity as the outer electron is easily lost as the attraction between the nucleus and electron decreases, because the electron is further away from the nucleus, the further down the group you go, low melting and boiling points, higher relative atomic mass - form ionic compounds with non-metals - they form 1+ ions - reaction with water produced hydrogen gas: when put in water they react vigorously - reaction with chloride produced salt - reaction with oxygen produced a metal oxide

Answer 14

- halogens: Fluorine is yellow, chlorine is green, bromine is red-brown, iodine is dark grey - as you go down the group halogens: become less reactive as it is harder to gain an extra electron because the outer shell's further from the nucleus, they have higher boiling and melting points, have a higher relative atomic mass - they form molecular compounds as they react with non-metals via covalent bonding - they form ionic bonds with metals: halogens form 1- ions (halides), the compounds that form have ionic structures - more reactive halogens will displace less reactive ones

Answer 15

- noble gases - eight electrons on outer shell (full outer shell) - monatomic gases (single atoms not bonded to each other) - colourless gases at room temperature - internet- non-flammable - as you go down the group boiling points of noble gases increase as well as number of electrons which leads to a greater intermolecular forces between them which they need to overcome