Ch.11- The Periodical Table

See your booklets  page 5

Atomic Number = protons, electrons (neutral)

Place them in “shells”  2,8,8,18,18…

Period 1

Period 2

Period 3

bability.

ISOTOPES –  Atoms of the same element that have different atomic masses….  they have the same atomic number(same number of protons/electrons) but they have different number of __neutrons__________.

How do you know that elements exist in isotopes?

(hint – look on the Periodic Table (P.T.))