
If the half-life of a sample of a radioactive substance is 30 seconds, how much would be left after 60 seconds? <span>
A. one-fourth</span>
True because they are organically made without any things that include chemicals
Electrons absorb energy, as they absorb energy they go from ground state to excited state and to return to ground state electrons release energy in the form of photons producing that color.
Answer:
mass and occupies space
Explanation:
matter is made up of mass and mass takes up space