Hello! Your answer will be C. If you need an explanation let me know!
I think it's between B) Benzene and C) Butane
The mass number of the atom is 21, the atomic number is 9, and the element is Fluorine. There are 9 protons, 9 electrons, 12 neutrons, and the elemental symbol is F.
<h3>Properties of an atom</h3>
For every atom:
- Protons and neutrons are located in the nucleus and the addition of both equals the mass number of atoms.
- Electrons are located outside the nucleus, in orbitals.
- Neutral atoms have the same number of electrons and protons
In the diagram:
Number of electrons = 9
Number of protons = 9
Number of neutrons = 12
Mass number = 12 + 9
= 21
Atomic number = number of protons
= 9
Element with atomic number 9 = Fluorine
Symbol of the element = F
More on atoms can be found here: brainly.com/question/1566330
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