Groups In The Periodic Table

Question 1

Why can some elements be classified as alkali metals?

Answer 1

If they have one electron in their outer shell

Question 2

Why can some elements be classified as halogens?

Answer 2

If they have seven electrons in their outer shell

Question 3

Why can some elements be classed as noble gases?

Answer 3

If they have a full outer shell (8 electrons)

Question 4

What are some properties of alkali metals?

Answer 4

• They are soft
• They have relatively low melting points

Question 5

How does Lithium react with water?

Answer 5

Lithium reacts violently with water, forming lithium hydroxide and highly flammable hydrogen

Question 6

How does Potassium react with water?

Answer 6

Potassium melts and floats. It moves very quickly on the surface. It is set on fire with a lilac flame has the hydrogen ignites.

Question 7

How does Sodium react with water?

Answer 7

When sodium is added to water, the sodium melts to form a ball that moves around on the surface

Question 8

What is the pattern in reactivity of the Alkali metals in terms of being with water?

Answer 8

The further down the group, the more vigorous the reaction there is with water

Question 9

Why does this pattern exist in terms of electronic configuration?

Answer 9

The outer electron gets further away from the nucleus as you go down the group.

Therefore the nucleus loses more control over it and the electron is more easily lost.

Question 10

What state and colour is chlorine at room temperature?

Answer 10

Yellowy green gas

Question 11

What state and colour is bromine at room temperature?

Answer 11

Reddish brown liquid

Question 12

What state and colour is iodine at room temperature?

Answer 12

Black Solid

Question 13

What is the pattern in the physical properties of the Halogens?

Answer 13

Halogens have low melting points and low boiling points. The melting and boiling points increase as you go down the group

Question 14

What is the chemical test for Chlorine?

Answer 14

Put some damp blue litmus paper into a test tube of the unknown gas. If the paper turns red and then is bleached white, the unknown gas is chlorine.

Question 15

How do halogens react with metals?

Answer 15

They form Metal Halides. Sodium reacts with Chlorine to from Sodium Chloride.

Question 16

What are some properties of Hydrogen Halides?

Answer 16

They dissolve in water to form acidic solutions

Question 17

What are Displacement reactions?

Answer 17

When a more reactive halogen takes the place of another. Fluorine + Sodium Chloride = Chlorine + Sodium Fluoride.

Question 18

Why are noble gases chemically inert?

Answer 18

Noble gases have full outer shells so they have no tendency to lose, gain or share electrons. Therefore they don’t take part in chemical reactions

Question 19

What are some patterns in physical properties of Noble Gases?

Answer 19

All noble gases have low boiling points, these boiling points increase as you go down the group.

The density of a noble gas increases as you go down the group.

Question 20

What are some uses of Noble Gases?

Answer 20

As helium has the lowest density (less dense than air) so it is used in balloons.

The noble gases are not flammable

Argon is used a shield gas when welding pieces of metal together so it stops air getting to the metal and oxidising it.