Question

give the number of valance and core electrons for each. valence electrons are from the group number. core electrons are not valence electrons. it is valence electrons that are gained or lost in a chemical reaction. mg has 9 valence electrons and 10 core electrons mg+2 has 11 valence electrons and 12 core electrons ar has 13 valence electrons and 14 core electrons a. 0 b. 1 c. 2 d. 3 e. 4 f. 5 g. 6 h. 7 i. 8 j. 9 k. 10 l. 11 m. 12 n. 13 o. 14 p. 15 q. 16 r. 17 s. 18 t. 19 u. 20

Explanation:

Step1: Determine Mg valence electrons

Magnesium (Mg) is in group 2 of the periodic table, so it has 2 valence electrons.

Step2: Determine Mg core electrons

Mg has an atomic number of 12. Core electrons = Atomic number - Valence electrons. So, 12 - 2=10 core electrons.

Step3: Determine Mg²⁺ valence electrons

Mg²⁺ is formed when Mg loses 2 electrons. So it has 0 valence electrons.

Step4: Determine Mg²⁺ core electrons

Mg²⁺ still has 10 core electrons as the loss of electrons is from the valence shell.

Step5: Determine Ar valence electrons

Argon (Ar) is a noble - gas in group 18. It has 8 valence electrons.

Step6: Determine Ar core electrons

Ar has an atomic number of 18. Core electrons = Atomic number - Valence electrons. So, 18 - 8 = 10 core electrons.

Answer:

Mg has C. 2 valence electrons and K. 10 core electrons
Mg⁺² has A. 0 valence electrons and K. 10 core electrons
Ar has I. 8 valence electrons and K. 10 core electrons