S4 Periodic Table

Question 1

Explain the similarities between elements in the same group of the Periodic Table in terms of electronic structure.

Answer 1

Elements in the same group have the same number of valence electrons and hence, similar chemical properties.

Question 2

Predict the properties of elements in group I. (7)

Answer 2

1) low melting and boiling points&decreases down the group
2) low densities that increase down the group
3) soft
4) compounds are ionic, soluble in water and have similar chemical formulas
5) known as alkali metals and react with cold water to form hydrogen and alkali.
6) reactivity increases down the group as the tendency to lose valence electrons increases down the group
7) powerful reducing agents

Question 3

What happens when lithium reacts with cold water?

Answer 3

It reacts quickly. Lithium floats on water and no flame is seen.

Question 4

What happens when sodium reacts with cold water?

Answer 4

It reacts very quickly. Sodium melts. The molten sodium darts around water. A yellow flame is seen.

Question 5

What happens when potassium reacts with cold water?

Answer 5

It reacts violently. Potassium melts and a lilac flame is seen.

Question 6

Predict the properties of elements in Group VII. (5)

Answer 6

1) diatomic
2) low melting and boiling point that increases down the group
3) color of halogens become darker down the group
4) reactivity decreases down the group as the tendency to gain electrons decreases down the group
5) a more reactive halogen displaces a less reactive halogen from its halide solution.

Question 7

What is the state and color of fluroine?

Answer 7

Pale yellow gas

Question 8

What is the state and color of chlorine?

Answer 8

Greenish-yellow gas

Question 9

What is the state and color of bromine?

Answer 9

Reddish brown liquid

Question 10

What is the state and color of iodine?

Answer 10

Black solid that sublimes to form violet vapour

Question 11

What are uses of noble gases? (4)

Answer 11

1) argon: fill lightbulbs
2) neon: advertising signs
3) helium: balloons
4) argon: manufacture of steel

Question 12

Why can halogen A displace halogen B from its halide solution?

Answer 12

A is more reactive than B, hence A can displace B from its halide solution.

Question 13

What are the properties of transition metals?

Answer 13

1) high melting points
2) high density
3) variable stable oxidation state
4) the elements and/or their compounds are often able to act as catalysts