Calculate the mass of:
(i) A single atom of silver (atomic mass of silver = 108 u).
(ii) A single molecule of CO₂.

To calculate the mass of an atom of silver and a molecule of CO2, you need to use the concept of atomic and molecular masses, which are expressed in unified atomic mass units (u or amu).

(i) Mass of an atom of silver (Ag):
The atomic mass of silver (Ag) is given as 108 u.

So, the mass of an atom of silver is 108 u.

(ii) Mass of a molecule of carbon dioxide (CO2):
A molecule of carbon dioxide (CO2) consists of one carbon atom (C) and two oxygen atoms (O). You can find the molecular mass of CO2 by adding the atomic masses of its constituent atoms.

Atomic mass of carbon (C) = 12 u (approximately)
Atomic mass of oxygen (O) = 16 u (approximately)
Now, add the atomic masses of one carbon atom and two oxygen atoms:

Molecular mass of CO2 = (1 × Atomic mass of C) + (2 × Atomic mass of O)
Molecular mass of CO2 = (1 × 12 u) + (2 × 16 u)
Molecular mass of CO2 = 12 u + 32 u
Molecular mass of CO2 = 44 u

So, the mass of a molecule of CO2 is approximately 44 u.