Group 2 - Halogens

Question 1

What happens with the atomic radius increases?

Answer 1

Atomic radius increases down the group. As one goes down the group, the atoms have more shells of electrons making the atom bigger.

Question 2

What happens with the melting point?

Answer 2

Melting points decrease down the group. The metallic bonding weakens as the atomic size increases. The distance between the positive ions and the delocalized electrons increases. Therefore the electrostatic attractive forces between the positive ions and the delocalized electrons weaken.

Question 3

What’s the trend with the 1st ionisation energy?

Answer 3

The outermost electrons are held more weakly as they are successively further from the nucleus in additional shells. In addition, the outer shell electrons become more shielded from the attraction of the nucleus by the repulsive force of inner shell electrons.

Question 4

What is the trend for reactivity?

Answer 4

Reactivity increases down the group.

Question 5

How does reactivity with water change as you go down group 2?

Answer 5

Increases ( Mg —–> Ba )
This is because outer electrons are further from the nucleus and more electron shielding, so more electrons are lost easily.

Question 6

What is use of barium sulfate?

Answer 6

In medicine to produce an X - ray image.

Question 7

Give one medical use of magnesium sulfate.

Answer 7

Milk of magneisa ; antacid to treat indigestion , heartburn, wind etc.