select the correct answer. which of these pairs of elements have the same number of valence electrons? a…

select the correct answer. which of these pairs of elements have the same number of valence electrons? a. oxygen (o) and bromine (br) b. selenium (se) and bromine (br) c. carbon (c) and lead (pb) d. oxygen (o) and carbon (c) e. sodium (na) and magnesium (mg)

select the correct answer. which of these pairs of elements have the same number of valence electrons? a. oxygen (o) and bromine (br) b. selenium (se) and bromine (br) c. carbon (c) and lead (pb) d. oxygen (o) and carbon (c) e. sodium (na) and magnesium (mg)

Answer

Explanation:

Step1: Recall valence - electron rules

Elements in the same group of the periodic table have the same number of valence electrons.

Step2: Analyze each option

  • Option A: Oxygen is in Group 16 with 6 valence electrons, Bromine is in Group 17 with 7 valence electrons.
  • Option B: Selenium is in Group 16 with 6 valence electrons, Bromine is in Group 17 with 7 valence electrons.
  • Option C: Carbon and lead are both in Group 14. Carbon has 4 valence electrons and lead also has 4 valence electrons.
  • Option D: Oxygen is in Group 16 with 6 valence electrons, Carbon is in Group 14 with 4 valence electrons.
  • Option E: Sodium is in Group 1 with 1 valence electron, Magnesium is in Group 2 with 2 valence electrons.

Answer:

C. carbon (C) and lead (Pb)