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

3

Step-by-step explanation:

when two lines are parallel, they have the same slope

you can find slop by changing the equation to slope intercept form (y=mx+b), m being the slope

slopes:

1. -2

2. -1/2

3. 2

4. 1/2