Which of the following has zero valency?

1. Hydrogen
2. Chlorine
3. Carbon
4. Neon

The valencies shown by copper is:

1. 1 and 2
2. 2 and 3
3. 2 and 4
4. 1 and 3

Assertion (A): When an atom gains one or more electrons, it becomes negatively charged.

Reason (R): The number of electrons in an atom exceeds the number of protons upon gaining electrons.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Assertion (A): Each element has its own unique symbol, which is a short hand representation of its atom.

Reason (R): The symbol of some elements is the same as the first letter of their names.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.