Answer:
180 mg
Explanation:
For a first-order reaction, we can calculate the amount of aspirine (A) at a certain time (t) using the following expression.

where,
k: rate constant
A₀: initial amount
If we know the half-life (
) we can calculate the rate constant.

When t = 4 h and A₀ = 400 mg, A is:

The answer is particels of nuclis
Answer:
Atoms
Explanation:
Energy, potential energy, is stored in the covalent bonds holding atoms together in the form of molecules. This is often called chemical energy.