Answer:
those are all physical changes and most physical changes can be undone like crushing a pice of metal you can flatten it back out you anwser is physical change
Explanation:
Physicist Ernest Rutherford<span> established the nuclear theory of the atom with his </span>gold-foil experiment<span>. When he shot a beam of alpha particles at a sheet of </span>gold foil<span>, a few of the particles were deflected. He concluded that a tiny, dense nucleus was causing the deflections.</span>
Well if you go to Quiz-let it gives the answer the mass of a mole of compound is determined by adding the atomic masses of the atoms making up the molecules
5mg in liter is 5 ppm
Explanation: 1 ppm is one part per million.
1 ppm is 1 mg is one part of million from 1 kg = 1000 000 mg
1 litre water is 1. Kg.
