Periodic table

Question 1

Give 3 features of the first periodic table

Answer 1

.Ordered by atomic weight
.contained gaps
.Sometimes, the order was changed so that elements with similar properties were in same group

Question 2

What tends to happen to metal elements

Answer 2

They lose electrons to form positive ions

Question 3

Why is helium a noble gas with only 2 electrons in its outer shell

Answer 3

It is the first shell so can hold a maximum of 2 electrons making it stable

Question 4

Does the reactivity of alkali metals increase up or down the group

Answer 4

Down

Question 5

What is formed when you react sodium with water

Answer 5

Sodium hydroxide AND hydrogen

Question 6

What is formed when you react lithium with oxygen and where

Answer 6

Lithium oxide on the surface of the alkali metal

Question 7

How would you describe an alkali metal’s ionic compound

Answer 7

Usually white or colourless crystals that produce colourless solutions when dissolved in water

Question 8

Describe the properties of a halogen molecule

Answer 8

.There is a single covalent bond between the atoms in the molecule
.Halogens always exist as small molecules

Question 9

Give 3 properties of alkali metals

Answer 9

.soft solids
.low melting and boiling points
.low densities (some float on water)

Question 10

Why are alkali metals stored in oil

Answer 10

They are very reactive and must be kept away from water/oxygen

Question 11

What happens when an alkali metal reacts with water

Answer 11

It forms hydrogen and a metal hydroxide

Question 12

What happens in a reaction between an alkali metal and chlorine

Answer 12

They react vigorously and Salts that are white or colourless crystals are formed

Question 13

Give 3 properties of metal hydroxides produced from alkali metal + water

Answer 13

.The metal hydroxide will always be alkali
.They are all soluble in water
.They form a colourless solution

Question 14

What state are these 4 halogens in at room temperature:
A: fluorine
B: Chlorine 
C: Bromine
D: Iodine

Answer 14

A: pale yellow gas
B: green gas
C: red/brown liquid
D: grey solid

Question 15

What happens to the reactivity of halogens down the group

Answer 15

It decreases

Question 16

Describe the melting points, boiling points and conductivity of halogens

Answer 16

.Low melting and boiling points

.Poor thermal and electrical conductors

Question 17

How could one show that chlorine is more reactive than bromine

Answer 17

Add chlorine to [soluble] bromide solution and bromine will be displaced

Question 18

Why do halogens have low melting and boiling points

Answer 18

They are small molecules with only a single covalent bond between the halogen atoms in their molecules

Question 19

Why do halogens become less reactive down the group

Answer 19

.Halogens react by gaining electrons

.As atoms get larger down the group there is less attraction due to shielding so it is harder to gain electrons

Question 20

Why are metals more reactive the further down the group

Answer 20

.React by losing electrons
.Larger atoms have more shells so more shielding blocking outer shell electrons from positive nucleus charge
.Outer shell electrons more easily lost so more reactive

Question 21

How are elements in the periodic table ordered

Answer 21

Atomic number

Question 22

Why do elements in the same group have similar chemical properties

Answer 22

They have the same number of electrons in their outer shell

Question 23

?

Answer 23

?

Question 24

No

Answer 24

No

Question 25

Why don’t noble gases form molecules easily

Answer 25

Their atoms have a stable arrangement of electrons

Question 26

What happens to the boiling point of noble gases down the group

Answer 26

It increases

Question 27

How do chlorine, bromine and iodine react with iron wool

Answer 27

All: produce flames
Chlorine - reacts very quickly
Bromine - must be heated as well as iron —> relatively slow
Iodine - both must be heavily heated —> very slow