Which of these pairs of elements have the same number of valence electrons? a. oxygen and bromineb) carbon and leadc) oxygen and carbond) sodium and magnesium

elements present in the same group in the periodic table will have same valence electrons

now look at periodic table and find out yourself

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year