What is the difference between a structural and inflation Epoch? (big bang eras)

 the difference between a Structure is from the Latin word structura which means "a fitting together, building." Although it's certainly used to describe buildings, it can do more than that and a In physical cosmology the inflationary epoch was the period in the evolution of the early universe when, according to inflation theory, the universe underwent an extremely rapid exponential expansion.

Explanation:

answer: 2×10^-2kg

explanation: density= mass per volume

vol=mass/density

converting to s.i units we have;

3÷1000kg = 0.003

1.5÷100m = 0.15

0.003/0.15 = 0.02kg