Atoms, Atoms Everywhere Round the mass number to the nearest whole number!

Be O Mg S Ar 4 4 5 2 2 -------- 8 8 2 6 8 -------- 12 12 12 2 8 2 15 P E N Electrons in 1st shell Electrons in 2nd shell Electrons in 3rd shell Be O Mg S Ar 4 4 5 2 2 -------- 8 8 2 6 8 -------- 12 12 12 2 8 2 15 15 16 2 8 5 16 16 16 8 6 2 18 8 18 22 2 8

a. The atomic number for Silicon is 14, how many protons are there b. The atomic number for Silicon is 14, how many electrons are there? ______ c. The atomic mass for Silicon is 28, how many neutrons are there? ________ d. There are 31 protons in an atom of Gallium, what is the atomic number? _____ e. How many neutrons are in an atom of Gallium if the atomic mass is 70? f. If there are 10 protons and 10 neutrons in an atom of Calcium, what is the atomic mass? _______ g. How many electrons are in an atom of Sulfur if the atomic number is 16? _____ h. How many electrons are in an atom of Potassium? _______ i. How many protons are in an atom of Potassium? ______ j. How many neutrons are in an atom of Potassium? _______ k. What is the atomic mass of Potassium? ______ l. What is the atomic number of Potassium? ________ m. What is the family or group number for Potassium? n. What is the row or period number for Potassium? 14 14 14 31 39 20 16 19 19 20 39 19 1 4

Beryllium Mass # ___ Atomic # ___ 9 4 4 5 P- N- 2 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 2

6 16 168 8 How many electrons are in the OUTERmost shell? _______ Oxygen Mass # ___ Atomic # ___ 168 P- N- 8 6 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 16

2 2 24 12 12 How many electrons are in the OUTERmost shell? _______ Magnesium Mass # ___ Atomic # ___ 24 12 12 P- N- 2 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 2

5 15 3115 1516 How many electrons are in the OUTERmost shell? _______ Phosphorus Mass # ___ Atomic # ___ 3115 P- N- 1516 5 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 15

6 16 3216 1616 How many electrons are in the OUTERmost shell? _______ Sulfur Mass # ___ Atomic # ___ 3216 P- N- 1616 6 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 16

8 18 4018 1822 How many electrons are in the OUTERmost shell? _______ Argon Mass # ___ Atomic # ___ P- N- 1822 8 How many electrons are in the OUTERmost shell? _______ What group # is it in? ________ 18