Topic 1

Question 1

What is an element

Answer 1

Elements consist of atoms with the same atomic number

Question 2

How to calaculate relative atomic mass

Answer 2

Sum of (isotope abundance x isotope mass number
_______________________
Sum of abundances of all the isotopes

Question 3

What is a compound

Answer 3

A substance formed by two or more atoms that are chemically bonded together

Question 4

What is a mixture and how can they be separated and give examples

Answer 4

A mixture has no chemical bonds and can be separated by physical methods eg filtration,crystaliseation,fractional distilleration,chromatography

Question 5

What is filtration and give an example

Answer 5

Filtration separates insoluble solids from liquids
It can be used for purification

Question 6

What is the first way you can separate soluble solids from solutions

Answer 6

Evaporation
Pour solution into evaporating dish
Heat solution,solvent will evaporate then getting more concentrated,the crystals will form
Keep heating till your left with dry crystals

Question 7

What is the second way you can separate soluable solids from solutions

Answer 7

Crystallisation
Pour solution into evap dish ,gentally heat ,some solvent will evap making solution more concentrated
When you see crystals start to form remove dish from heat and leave to cool
Salt should start to form crystals as it becomes insoluble to cold and place in warm place to dry

Question 8

What is fractional distilleration

Answer 8

Used to separate a mixture of liquids

Question 9

Decribe the practical of distilleration

Answer 9

put mixture in flask and put fracturing column on top then heat it
Diff liquids will have diff boiling points and evap at diff temps
Liquid with lowest boiling point evap a first ,when the temp on thermometer matches boiling point of liquid it will reach top of column
When first liquid has been collected raise temp UNTILL next one reaches top

Question 10

Who described atoms as solid spheres

Answer 10

John dalton

Question 11

What did jj Thomson conclude from his exeripemts

Answer 11

That atoms wernt solid spheres
His measurements of charge and mass shows that an atom must contain even smaller and negatively charged particles

Question 12

What did the solid sphere idea get changed to

Answer 12

Plum pudding model

Question 13

What does the plum pudding model show

Answer 13

Ball of positive charge with electrons stuck in

Question 14

What did Rutherford show

Answer 14

That the plum pudding model is wrong

Question 15

In 1909 what happened

Answer 15

Rutherford and marsden conducted alpha particle scattering experiments

Question 16

What is the alpha particle scattering experiments

Answer 16

Fired positvely charged alpha particles at and extremely thing peice of gold

Question 17

How did the alpha particle scatting experiment prove that the plum pudding wasn’t right

Answer 17

The expectation was that only the particles would pass through the sheet or be slightly deflected due to the positive charge of each atom being spread out
However while most going through some were deflected more than expected and a small number were deflected backwords so plum pudding couldn’t be right

Question 18

What idea did Rutherford come up with to explain this new evidence

Answer 18

The nuclear model
Where there’s a tiny positively charged Nucleas at the centre where most mass is concentrated

Question 19

How did rutherfords nuclear model differ from bohrs model

Answer 19

Rutherford thought that electrons clouded the nucleus so most of atom is empty space
Bohr suggest that electrons were in shells that orbit the nucleus

Question 20

In the 1800 how were elements arranged

Answer 20

By atomic weight

Question 21

How were the early periodic tables wrong

Answer 21

They were not complete and some events were places in wrong group due to elements being placed in order of atomic weight and did not take into account of their properties

Question 22

Why were gaps left in dmitri Mendeleev table of elements

Answer 22

Because there was undiscovered elements and allowed Mendeleev to predict what properties they had

Question 23

What are group 1 called

Answer 23

Alkali metals

Question 24

What are the properties of the group 1 element

Answer 24

Soft ,low density and the first 3 elements are less dense than water

Question 25

Why are the alkali metals very reactive

Answer 25

Due to them only having 1 electron in outer shell

Question 26

What are the trends for the alkali metals as you go down the group

Answer 26

Increasing reactivity
Due to electron being further away from nucleus
Lower melting point and boiling point
Higher relative atomic mass

Question 27

What are the propers ionic compounds of alkali metals

Answer 27

Usually white solids that dissolve in water to produce a colourless solution

Question 28

What happens when alkali metals react with water

Answer 28

React vigously to prouduce hydrogen gas and metal oxides
The more reactive the more violent it is
The energy given out also increases

Question 29

What happens when you react a alkali metal with chlorine

Answer 29

React vingoursly when heated in chlorine gas to form white metal chloride salts
As you go down the group reactivity increases making reaction more vigouros

Question 30

What happens when you react a alkali metal with oxygen

Answer 30

Lithium reacts to form lithium oxide
Sodium reacts to form a mixture of sodium oxide and sodium peroxide
Potassium reacts to form a mixture of potassium peroxide and potassuim superoxide

Question 31

What are the halogens colours vapours

Answer 31

Fluorine poisionous yellow gas
Chlorine fairly reactive dense green gas
Bromine dense poisonous red brown volitile liquid
Iodine dark dark grey crystalline solid or purple vapour
All in pairs

Question 32

What trends happen in group 7

Answer 32

Become less reactive harder to gain an extra electron
Higher melting and boiling points
Higher relative atomic masses

Question 33

What are halogens that form ionic bonds with metals called

Answer 33

1- ions called halides

Question 34

What happens with more reactive halogens

Answer 34

They will displace less reactive ones

Question 35

Properties of noble gasses

Answer 35

Monatomic gases
Coulorless gasses at room temps
Non flammable due to them being inert

Question 36

What happens to the boiling points of the halogens as you go down the group

Answer 36

Boiling points increase