Groups in the Periodic Table (2)

Question 1

What are the

alkali metals?

Answer 1

all the elements in group 1 of the periodic table

Question 2

What are some key properties of

all alkali metals?

• colour?
• storage?
• handling?
• reactivity?
• melting and boiling points?
• softness/hardness?
• bonding?

Answer 2

• silvery solids
• have to be stored in oil
• have to be handled with forceps (they can cause chemical burns on the skin)
• very reactive
• have low melting and boiling points
• very soft
• only form ionic bonds

Question 3

What is the relationship between

periods in the periodic table and reactivity?

(specifically for group 1) and why?

Answer 3

the lower down the column you go, the more easily the outer electron is lost because it is further from the nucleus (so the atomic radius is longer) and it’s less strongly attracted to the nucleus, so less energy is needed to remove it

Question 4

What is the general equation for the reaction of an

alkali metal with water?

Answer 4

alkali metal + water -> metal hydroxide + hydrogen

Question 5

What are the visible observations of reacting

lithium with water?

(period 1)

Answer 5

it will move around the surface of the liquid, fizzing furiously

Question 6

What are the visibal observations of reacting

sodium with water?

(period 2)

Answer 6

it will move around the surface of the liquid, fizzing furiously
it will also melt in the heat of the reaction

Question 7

What are the visibal observations of reacting

potassium with water?

(period 3)

Answer 7

it will move around the surface of the liquid, fizzing furiously
it will also melt in the heat of the reaction
it will get hot enough to ignite the hydrogen gas being produced

Question 8

What are the

halogens?

Answer 8

the elements in group 7 of the periodic table

Question 9

What is a similarity of

halogens?

Answer 9

they exist as diatomic molecules

Question 10

What are some trends of

halogens?

(3)

Answer 10

As you go down the column:
- their melting and boiling points increase
- their colours get darker
- they get less reactive

Question 11

What is

chlorine

at room temperature? (period 2)

Answer 11

a fairly reactive, poisonous, green gas

Question 12

What is

bromine

at room temperature? (period 3)

Answer 12

a poisonous, red-brown liquid which gives off an orange vapour

Question 13

What is

iodine

at room temperature? (period 4)

Answer 13

a poisonous, dark grey crystalline solid which gives off a purple vapour when heated

Question 14

Describe a

test for chlorine gas.

(3 steps)

Answer 14

1. Collect the gas in a test tube.
2. Put a strip of damp blue litmus paper into the tube.
3. If chlorine is present, the litmus paper will bleach and turn white.

It may turn red for a moment (because the chlorine is acidic.

Question 15

Why do

halogens get less reactive as you go down the column?

Answer 15

it is harder for the halogen to attract an electron (and form an ion) when the atomic radius gets larger because the outer shell is further away from the nucleus

Question 16

What happens when you react a

halogen with a metal?

Answer 16

they will react vigorously to form salts called ‘metal halides’

Question 17

What happens when you react a

halogen with hydrogen?

Answer 17

hydrogen halides are formed

Question 18

What are some properties of

hydrogen halides?

• solubility?
• acidity?

Answer 18

• soluble
• dissolve in water to form acidic solutions

Question 19

How can you

use displacement reactions to show the reactivity trend of halogens?

(4 steps)

Answer 19

1. Measure out a small amount of halide salt solution in a test tube.
2. Add a few drops of a halogen solution to it and shake the tube gently.
3. If you see a colour change, then a reaction has happened - the halogen has displaced the halide ions from the salt. If no reaction happens, there won’t be a colour change - the halogen is less reactive than the halide so can’t displace it.
4. Repeat the process using different combinatinos of halide salt and halogen.

Question 20

What are the

noble gases?

Answer 20

the elements in group 0

Question 21

What are some key properties of

noble gases?

(4 things)

Answer 21

• inert (don’t react much at all)
• non-flammable
• colourless monatomic gases (at room temperature)
• very low densities

Question 22

What are the

trends in physical properties of noble gases?

(2)

Answer 22

as you go down the column:
- density increases
- melting and boiling points increases