Topic 4 - Groups in the Periodic Table

Question 1

What are most of the elements in the periodic table?

Answer 1

Metals

Question 2

Where are the metals on the periodic table?

Answer 2

Everywhere apart from the far right

Question 3

Where are the transition metals?

Answer 3

The middle block

Question 4

What are some of the properties of metals?

Answer 4

• Conduct electricity well

- Malleable (bent or hammered into different shapes)

Question 5

What are some uses of metals based on their properties?

Answer 5

• Electrical wires (electrical conductivity)

- Bridges/car bodies (malleable)

Question 6

What are some of the properties of transition metals?

Answer 6

• High melting points

- Form colourful compounds (use in hair dyes, colour in gemstones, colours in pottery glazes)

Question 7

How are metals structured?

Answer 7

Regular arrangement of atoms held together with metallic bonds

• Metallic bonds give metal giant structure of +ve ions + free electrons as metallic bonds allow outer electrons of each atom to become delocalised
• Creates sea of delocalised electrons (hence metal’s electrical conductivity)
• Giant metallic structure = high melting/boiling points + are insoluble
• Allow layers of atoms to slide over each other so can be bent/shaped (hence malleability)

Question 8

Where are the alkali metals on the periodic table?

Answer 8

Group 1

Question 9

What are the properties of the alkali metals?

Answer 9

• Soft (can be cut w/ a knife)

- Low melting points compared to other metals

Question 10

How do the Group 1 elements react with water?

Answer 10

• Lithium, sodium or potassium react vigorously to form hydroxides
• Makes an alkaline solutions (hence alkali metals)

Question 11

Why do the elements in Group 1 get more reactive as the atomic number increases?

Answer 11

Have more electrons so more electrons shells so further from nucleus so less attraction between negative electrons + positive nucleus

Question 12

What does the reaction between an alkali metal and water produce?

Answer 12

-Hydrogen (what you see fizzing)

Alkali metal + water –> alkaline solutions [hydroxide] + hydrogen

Question 13

How do you test for hydrogen?

Answer 13

A lighted splint will squeak if hydrogen is present

Question 14

Which Group are the halogens?

Answer 14

7

Question 15

What are the properties of chlorine (halogen) at room temperature?

Answer 15

• Fairly reactive
• Poisonous
• Dense green gas

Question 16

What are the properties of bromine (halogen) at room temperature?

Answer 16

• Dense
• Poisonous
• Orange liquid

Question 17

What are the properties of iodine (halogen) at room temperature?

Answer 17

Dark grey crystalline solid

Question 18

What is the general word equation of the reaction between a metal and a halogen?

Answer 18

Metal + halogen –> metal halide

Question 19

What is the general equation for the reaction between a halogen and hydrogen?

Answer 19

Halogen + hydrogen –> hydrogen halide

Question 20

What is a property of hydrogen halides?

Answer 20

Soluble - dissolve in water to form acidic solutions

Question 21

How do halogens displace each other?

Answer 21

• Higher in Group 7 = more reactive as outer shell nearer nucleus so pull of +ve nucleus = greater to electrons
• Halide dissolves in water so halide ions free to react
• More reactive halogen reacts w/ solution containing halide ions pushing out less reactive
• This is a displacement reaction
• e.g. Cl~2(g) + 2KI(aq) –> I~2(aq) + 2KCl(aq)

Question 22

What group are the noble gases?

Answer 22

0

Question 23

What are the properties of the noble gases?

Answer 23

• Colourless gas at room temp
• Inert (don’t react much) as have full outer shell
• Non flammable

Question 24

How were the noble gases discovered?

Answer 24

• Chemists noticed density of nitrogen made in chemical reactions different to density of nitrogen taken from air
• Hypothesised nitrogen from air must have other gases
• Discovered them by experiments incl. fractional distillation of air

Question 25

What are the everyday uses of argon?

Answer 25

• Provide inert atmosphere in filament lamps
• Non flammable so stops hot filament burning away
• Protects metals being welded
• Inert so stops metal reacting w/ oxygen

Question 26

What are the everyday uses of helium?

Answer 26

• Airships + party balloons

- Lower density than air so floats

Question 27

What are the patterns in the properties of the noble gases?

Answer 27

Boiling points + densities increase as go down the group