Group 1 - Paper 2

Question 1

What does a group correspond to on the periodic table?

Answer 1

The group of an element is its vertical position on the periodic table, equal to the number of electrons in its outer shell.

Question 2

Describe 2 properties of alkali metals?

Answer 2

Alkali metals are soft, and has relatively low melting points.

Question 3

Describe the reaction of lithium with cold water.

Answer 3

Lithium floats. It fizzes steadily and becomes smaller, until it eventually disappears.

Question 4

Describe the reaction of sodium with cold water.

Answer 4

Sodium melts to form a ball that moves around on the surface. It fizzes rapidly before it disappears.

Question 5

Describe the reaction of potassium with cold water.

Answer 5

Potassium melts and floats. It moves around very quickly on the surface of the water. The metal self-ignites, which also ignites the hydrogen gas. This results in sparks and a lilac flame. There is sometimes a small explosion at the end of the reaction.

Question 6

Describe the pattern in reactivity of the alkali metals with cold water.

Answer 6

The speed and violence of the reaction increases as you go down the group. This shows that the reactivity of the alkali metals increases as you go down the group.

Question 7

Explain the pattern in reactivity of the alkali metals in terms of electronic configuration.

Answer 7

The reactivity of Group 1 elements increases as you go down the group because the atoms get larger and the outer electron gets further from the nucleus.
Therefore the attraction between the nucleus and outer electron gets weaker, so the electron is more easily lost.