Which of the following properties does not match with the elements of the halogen family ?

1. They have seven electrons in their valence shell.
2. They are highly reactive chemically.
3. They are metallic in nature.
4. They are diatomic in their molecular form.

With reference to the variation of properties in the Periodic Table, which of the following is generally true?

1. Atomic size increases from left to right across a period.
2. Ionization potential increases from left to right across a period.
3. Electron affinity increases going down a group.
4. Electronegativity increases going down a group.

The number of electrons in the valence shell of a halogen is :

1. 1
2. 3
3. 5
4. 7

Among period 2 elements, the element which has highest electron affinity is :

1. Lithium
2. Carbon
3. Chlorine
4. Fluorine