When a metal atom becomes an ion:

1. It loses electrons and is oxidized.
2. It gains electrons and is reduced.
3. It gains electrons and is oxidized
4. It loses electrons and is reduced.

An element Y has 2 electrons in the 2nd orbit and X has 7 electrons in its 3rd orbit. The compound formed between them has the formula:

1. XY₂
2. YX₂
3. YX
4. Y₇X₂

Postulates of modern atomic theory are:

P — Atoms of an elements may not be alike.

Q — Atoms of elements combine in small whole numbers to form molecules.

R — Atoms can neither be created nor destroyed.

1. Only P
2. Only Q
3. Only R
4. Both P and Q

An atom is electrically neutral because :

P — Electrons, protons and neutrons are equal in number.

Q — Protons are equal to neutrons.

R — Protons are equal to electrons.

1. Only P
2. Only Q
3. Only R
4. Both Q and R