Bohr (Nuclear Model of Atom)

Electron (e^-)

Protons (P)

원소번호 = proton의 개수

Neutron (n^-)

Isotopes

Have number of protons but different number of neutrons

ex) Fluorine (F) has 9 electrons.

An Atom is neutral if e^- = P
If an atom gains an electorn, it will become negatively charged (anions).
If an atom loses an electron, it will become positively charged (cations).
Number of protons is not changed.

	P	e-
Na	11	11
Na+	11	10
O	8	8
$O_{2}$	8	10

Isotopic Symbol	Atomic Number	Mass Number	Number of Electrons	Number of Protons	Number of Neutrons (Mass # - Proton #)
112Cd	48	112	48	48	64