Group 1 - The Alkali Metals/ Group 7 - The halogens

Question 1

Name the first three elements in group 1.

Answer 1

Lithium
Sodium
Potassium

Question 2

Do group 1 metals have high or low densities?

Answer 2

They have low densities that gradually increase as you go down the group.

Question 3

Why do the 1st three elements in group 1 float on water?

Answer 3

The density of the first three elements is lower than the density of water (g/cm^3).

Question 4

Why do group 1 metals form ions with +1 charge when they react with non metals?

Answer 4

They lose an electron making the overall charge. positive.

Question 5

How are group 1 metals stored?

Answer 5

They are stored in oil, because if they react with oxygen because if they do a white oxide begins to form on the surface.

Question 6

Name the 1st four elements in group 7.

Answer 6

Fluorine
Chlorine
Bromine
Iodine

Question 7

Name the state of the halogens at room temperature.

Answer 7

Fluorine and Chlorine are gases
Bromine is a liquid
Iodine and Astatine are solids

Question 8

In the halogens, do the melting and boiling points increase/decrease?

Answer 8

The increase as you go down the group.

Question 9

Why do group 7 non-metals form a -1 ion?

Answer 9

They only have to gain one electron to have a full shell. Overall the charge would be negative.

Question 10

Describe the reactivity in group 7.

Answer 10

Halogens are highly reactive non-metals because they need one more electron to achieve a full outer shell.
Reactivity decreases down the group because it becomes harder for larger atoms to attract an extra electron due to increased shielding and atomic size.

Question 11

Describe the reactivity in group 1.

Answer 11

Reactivity increases down the group, from lithium to francium.
Group 1 metals are so reactive that they are stored in oil to prevent contact with air or moisture.
They react violently with water, oxygen, and halogens, forming compounds like hydroxides, oxides, and salts