The answer is D they have 4 neutrons
Answer:
If an atom, ion, or molecule is at the lowest possible energy level, it and its electrons are said to be in the ground state. If it is at a higher energy level, it is said to be excited, or any electrons that have higher energy than the ground state are excited
Explanation:
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Answer:
Salt
Explanation:
Because Na is sodium which is salt
Answer:
D. Protons ; neutrons.
Explanation:
For a given element the number of protons is fixed, but the number of neutrons differ because the element usually consist of a number of isotopes.
For example Carbon has isotopes which contain 12, 13 and 14 neutrons.
So that is why you average the number of neutrons to find the approximate atomic mass..