Question

element atomic number # of protons # of electrons # of valence electrons circle the correct response + number of electrons to achieve a full outer shell. oxidation number (example) hydrogen 1 1 1 1 gain lose gain/lose neither 0 1 2 3 4 electrons 1+/- 10) neon 10 gain lose gain/lose neither 0 1 2 3 4 electrons 11) sodium 11 gain lose gain/lose neither 0 1 2 3 4 electrons 12) magnesium 12 gain lose gain/lose neither 0 1 2 3 4 electrons 13) aluminum 13 gain lose gain/lose neither 0 1 2 3 4 electrons 14) silicon 14 gain lose gain/lose neither 0 1 2 3 4 electrons 15) phosphorus 15 gain lose gain/lose neither 0 1 2 3 4 electrons 16) sulfur 16 gain lose gain/lose neither 0 1 2 3 4 electrons 17) chlorine 17 gain lose gain/lose neither 0 1 2 3 4 electrons 18) argon 18 gain lose gain/lose neither 0 1 2 3 4 electrons 19) potassium 19 gain lose gain/lose neither 0 1 2 3 4 electrons 20) calcium 20 gain lose gain/lose neither 0 1 2 3 4 electrons

Explanation:

10) Neon

Step1: Determine protons, electrons

Atomic number = number of protons = number of electrons (neutral atom). Neon's atomic number is 10, so protons = 10, electrons = 10.

Step2: Valence electrons

Neon is a noble gas, valence electrons = 8 (full outer shell).

Step3: Electron gain/lose

Since outer shell is full, it does neither gain nor lose electrons.

Step4: Oxidation number

Noble gases have oxidation number 0 (usually).

Step1: Protons, electrons

Atomic number 11, so protons = 11, electrons = 11.

Step2: Valence electrons

Sodium is in group 1, valence electrons = 1.

Step3: Electron gain/lose

To achieve full outer shell (8 electrons), it loses 1 electron (easier to lose 1 than gain 7).

Step4: Oxidation number

Losing 1 electron gives +1 oxidation number.

Step1: Protons, electrons

Atomic number 12, protons = 12, electrons = 12.

Step2: Valence electrons

Group 2, valence electrons = 2.

Step3: Electron gain/lose

Loses 2 electrons to achieve full outer shell (8 electrons).

Step4: Oxidation number

Losing 2 electrons gives +2 oxidation number.

Answer:

Element	Atomic Number	# of Protons	# of Electrons	# of Valence Electrons	Circle (GAIN/LOSE/NEITHER + electrons)	Oxidation Number

11) Sodium