The protons in an nucleus of an atom will not change unless a nuclear reaction takes place. The number of protons is equal to the atomic number of the element. For a neutral atom, the number of electrons and protons are equal. When they are unequal, then the atom occurs as an ion. It will has a net charge with it. The ion O²⁻ has a net charge of negative positive 2 because it has 2 more electrons than its protons. Since neutral oxygen has 8 protons, then O²⁻ ion has 8 protons and 10 electrons.
A. Excretion
(Word cap fill)
Plants can grow from sunlight and water.
Answer:
Average atomic mass = 6.6575.
Explanation:
As fractions the abundance is 1/4 and 3/4.
The average atomic mass = (5.03 + 3(7.20) / 4
= 6.6575.