Final answer:
The density of a neutron star is closest to 1 billion tonnes/teaspoon.
Step-by-step explanation:
The density of a neutron star is 3.4 × 1018 kg/m³. The density of a hydrogen nucleus is 6.0 × 1017 kg/m³. Therefore, the neutron star is 5.7 times denser than the hydrogen nucleus. To compare this density to the given options, we can convert it to different units.
Option a) 10 kg/teaspoon is equivalent to 1.0 × 109 kg/m³.
Option b) 1 tonne/cubic centimeter is equivalent to 1.0 × 1012 kg/m³.
Option c) 5 tonnes/teaspoon is equivalent to 2.5 × 1013 kg/m³.
Option d) 1 billion tonnes/teaspoon is equivalent to 1.0 × 1017 kg/m³.
Comparing the densities, we find that the density of a neutron star (3.4 × 1018 kg/m³) is closest to Option d) 1 billion tonnes/teaspoon.