Question

part 1: the atomic cheat sheet
before we start, lets remember the \big three\ rules:

1. atomic number = number of
2. atomic mass = + neutrons.
3. neutral atoms = protons and electrons are always

part 2: element math practice
fill in the missing blanks for each element below. you may need a periodic table to help you!

element name

atomic number

number of protons

number of neutrons

atomic mass

number of electrons.

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magnesium

oxygen

neon

nitrogen

helium

Explanation:

Step1: Fill "Big Three" rules

1. Atomic Number = Number of $\text{Protons}$
2. Atomic Mass = $\text{Protons}$ + Neutrons
3. Neutral Atoms = Protons and Electrons are always $\text{equal}$

Step2: Get Magnesium data

From periodic table: Atomic Number = 12. Protons = Atomic Number = 12. Electrons = Protons = 12. Atomic Mass = 24.305, round to 24. Neutrons = $24 - 12 = 12$.

Step3: Get Oxygen data

From periodic table: Atomic Number = 8. Protons = 8. Electrons = 8. Atomic Mass = 16.00, round to 16. Neutrons = $16 - 8 = 8$.

Step4: Get Neon data

From periodic table: Atomic Number = 10. Protons = 10. Electrons = 10. Atomic Mass = 20.18, round to 20. Neutrons = $20 - 10 = 10$.

Step5: Get Nitrogen data

From periodic table: Atomic Number = 7. Protons = 7. Electrons = 7. Atomic Mass = 14.01, round to 14. Neutrons = $14 - 7 = 7$.

Step6: Get Helium data

From periodic table: Atomic Number = 2. Protons = 2. Electrons = 2. Atomic Mass = 4.00, round to 4. Neutrons = $4 - 2 = 2$.

Answer:

Part 1 Completed Rules:

1. Atomic Number = Number of $\text{Protons}$
2. Atomic Mass = $\text{Protons}$ + Neutrons
3. Neutral Atoms = Protons and Electrons are always $\text{equal}$

Part 2 Completed Table:

Element Name	Atomic Number	Number of Protons	Number of Neutrons	Atomic Mass	Number of electrons
Oxygen	8	8	8	16	8
Neon	10	10	10	20	10
Nitrogen	7	7	7	14	7
Helium	2	2	2	4	2