Proton plus neutron is the correct answer. Protons and neutrons have a mass of 1 and electrons have a mass of 0. So in order to find the mass of an atom you need to add the number of protons and the number of neutrons.
Choice c - eats away other materials
Answer: Explanation:
Calcium (Ca), chemical element, one of the alkaline-earth metals of Group 2 (IIa) of the periodic table. It is the most abundant metallic element in the human body and the fifth most abundant element in Earth's crust.
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Calcium.
atomic number 20
oxidation state +2
electron configuration 1s22s22p63s23p64s2
Explanation:
The higher levels of gravity put on an object the more weight the object has. For example someone who weighs say 100 lbs would weigh more if higher amounts of gravity would be applied to them. And less if less gravity was applied. But larger objects will automatically have more gravity applied to them than something smaller due to the gravitational pull needing to pull harder to keep the object to the planet's surface. Hope this helps! :)