Answer: The answer would be minerals. Synthetics are made by men, and shouldn't be found in the earth Vitamins are organic Cement is a mixture of an organic compounds and rarely found in nature.
A pure substance hope this helped
Choose new balls (which is A I believe)
Approximately 99 because there is the same amount of electrons and the only things that go into the nucleus is protons and neutrons.
This is the electron configuration of neptunium:
<span>Rn 5f4 6d1 7s2
</span>or, if you want to complicate:
<span>1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f4 6d1
</span>Since there are 93 electrons, they make up 5f4 altogether.
