4. Assign an oxidation state to the element whose atom is underlined in the following compound: AIH3 O Al: +5
O Al: -5
Ο Ο Ο
Al: -3
O Al: +3

The oxidation state of Al in is +3.

Explanation:

The number attained by an atom or substance due to loss or gain of electrons is called oxidation state.

For example, in it is known that the oxidation state of hydrogen is -1 as aluminum is a cation so it cannot have an oxidation state as 'minus'.

Whereas hydrogen has the property to act both as a cation and an anion.

Let us assume the oxidation state of Al is x in the compound .

Hence, oxidation state of Al is calculated as follows.

This means that the oxidation state of Al in is +3.

Thus, we can conclude that oxidation state of Al in is +3.

4d^55s^1 ( third choice)

intermolecular forces are the forces between molecules or particles.

there are two kinds of van der waals forces: weak london dispersion forces and stronger dipole-dipole forces.

in molecule of water there are dipole-dipole forces between negatively charged oxygen from one molecule of water and positively charger hydrogen of another molecule of water.

hydrogen bond is an electrostatic attraction between two polar groups that occurs when a hydrogen atom (h), covalently bound to a highly electronegative atom such as flourine (f), oxygen (o) and nitrogen (n) atoms.