Basic is the answer. (i think so)
1 Kg = 1,000g
Therefore 1.33 × 10^-7 g = 1.33 × 10^-10 kg
1m³ = 1,000,000cm³
Therefore 1 cm³ = 1 × 10^-6 m³
Dividing the mass per unit volume you get:
(1.33 × 10^-10 kg) ÷ (1 × 10^-6 m³)
= 1.33 × 10^(-10--6) = 1.33 × 10^(-10 + 6) = 1.33 × 10^-4 kg/m³
Density = 1.33 × 10^-4 kg/m³
Protons do not move out of the nucleus of atoms although they repel each other.
Remember that protons are particles with positive charge and they held together in the nucleus of the atom which is a tiny tiny region. As you know, like charges repel each other, which means that the protons exert a repulsion force.
The correct answers would be B, and d