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. o has 9 valence electrons and 10 core electrons o^-2 has 11 valence electrons and 12 core electrons ne 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 valence and core electrons of O

Oxygen (O) is in group 16 of the periodic table. It has 8 electrons in total. The number of valence electrons is equal to the group - number minus 10 (for main - group elements in groups 13 - 18), so for O, the number of valence electrons is 6. The number of core electrons is \(8 - 6=2\).

Step2: Determine valence and core electrons of \(O^{2 -}\)

\(O^{2 -}\) is the oxygen anion with a 2 - negative charge. It has gained 2 electrons, so it has a total of \(8 + 2=10\) electrons. Since it is still in group 16, the number of valence electrons is 8 (it has a full outer - shell after gaining 2 electrons), and the number of core electrons is \(10 - 8 = 2\).

Step3: Determine valence and core electrons of Ne

Neon (Ne) is in group 18 of the periodic table. It has 10 electrons in total. The number of valence electrons is 8 (a full outer - shell), and the number of core electrons is \(10 - 8=2\).

Answer:

O has G. 6 valence electrons and A. 2 core electrons
\(O^{2 -}\) has I. 8 valence electrons and A. 2 core electrons
Ne has I. 8 valence electrons and A. 2 core electrons