C2.4 Groups in the periodic table

Question 1

What affects the properties of a material?

Answer 1

The type of chemical bonding it has

Question 2

What are covalent bonds?

Answer 2

Atoms that share electrons to get a full other shell, covalent bonds hold atoms together in molecules

Question 3

What two types of bonds have high melting and boiling points?

Answer 3

Ionic and giant molecular covalent

Question 4

What type of bond has low melting and boiling points?

Answer 4

Simple molecular covalent

Question 5

What is the solubility of ionic, simple covalent and giant covalent bonds?

Answer 5

Ionic- many dissolve in water
Simple molecular covalent- some dissolve in water
Giant molecular covalent-insoluble in water

Question 6

When do ionic bonds form?

Answer 6

When a metal reacts with a non-metal

Question 7

When do covalent bonds form?

Answer 7

Between atoms of non-metal elements

Question 8

What are the atoms in metals held together by?

Answer 8

Metallic bonds

Question 9

What are some properties of metals?

Answer 9

• good conductors of heat and electricity
• don’t dissolve in water
• malleable

Question 10

What are delocalised electrons?

Answer 10

Electrons that are not located at specific atoms

Question 11

In what way do the delocalised electrons move between the positive ions?

Answer 11

Randomly in all directions

Question 12

What happens to the electrons if a potential difference is applied to the metal?

Answer 12

The electrons start to drift off in one direction

Question 13

What is the movement of electrons in one direction in an element called?

Answer 13

An electric current

Question 14

Why are metals malleable?

Answer 14

The positive ions in a metal can slide over each other, and since they are still held together by sea of electrons the metal spreads out instead of breaking

Question 15

What are two properties of transition metals?

Answer 15

They have high melting points and form coloured compounds

Question 16

Where are most metals found in the periodic table?

Answer 16

In the central block where the transition metals are found

Question 17

Where are the alkali metals found in the periodic table?

Answer 17

Group 1

Question 18

What are two properties of alkali metals?

Answer 18

• solid at room temperature but have a low melting point in comparison to other metals
• they are all soft metals that can be cut with a knife

Question 19

What forms as a result of an alkali metal reacting with water?

Answer 19

A metal hydroxide and hydrogen gas

Question 20

Are metal hydroxides acidic or alkaline?

Answer 20

Alkaline

Question 21

Why are the reactions of all alkali metals similar?

Answer 21

They all form ions with a charge of +1

Question 22

What happens to the reactivity of alkaline metals as you go down the group?

Answer 22

It increases

Question 23

Why does reactivity increase as you go down a group?

Answer 23

The further you go down a group the more electron shells they have. The further the electron shells are from the nucleus, the smaller the force between the positive charge of the nucleus and negative charges of the electrons, which means they are more likely to lose or gain an electron to gain a full outer shell

Question 24

Where are the halogens found?

Answer 24

Group 7

Question 25

What are two properties of halogens?

Answer 25

• they are all coloured elements

- they are all corrosive and toxic

Question 26

What is produced from a reaction between a metal and a halogen?

Answer 26

A metal halide

Question 27

Why do halogens all form ions with a charge of -1?

Answer 27

They are all missing an electron to complete their outer shell so they gain an electron and become negative

Question 28

What is the most reactive halogen?

Answer 28

Fluorine

Question 29

What is the least reactive halogen?

Answer 29

Iodine

Question 30

What is a displacement reaction?

Answer 30

When a more reactive metal displaces a less reactive one from a compound

Question 31

What happens when you dissolve a hydrogen halide in water?

Answer 31

It becomes an acid

Question 32

What happens to a solution of sodium bromide when chlorine is added?

Answer 32

Chloride displaces the bromine salt and the solution turns from colourless to clear

Question 33

What happens to a solution of potassium iodide when chlorine is added?

Answer 33

Chlorine displaces the iodide and the solution turns brown-black

Question 34

Where are the noble gases found?

Answer 34

Group 0

Question 35

What does it mean when an element is inert?

Answer 35

It is very hard to make them react

Question 36

Why are group 0 elements inert?

Answer 36

They have full outer shells

Question 37

How do elements in other groups gain full electron shells?

Answer 37

By forming ions or covalent bonds

Question 38

Why are noble gases useful?

Answer 38

Because they are unreactive

Question 39

What are some uses of noble gases?

Answer 39

• xenon and argon used to be used in filament lamps the stop the hot filament from reacting with oxygen and burning away
• argon and helium are used in welding, to form a blanket over the hot metal to stop it reacting with oxygen in the air
• argon is used in fire-extinguishing systems because it is non-flammable
• helium is used for filling up balloons and airships because of its low density
• neon is used in fluorescent lamps and advertising displays as it produces a red coloured light when an electric current is passed through the tube at low pressure