Question

the diagram below shows a portion of the periodic table of the elements with oxygen magnified in size.
what is oxygens atomic number?
a. 15.994
b. o
c. 6a
d. 8

Explanation:

In the periodic table, the atomic number is the number at the top of an element's cell. For oxygen ($O$), this number is clearly shown as $8$. Option A ($15.994$) is the atomic mass. Option B ($O$) is the chemical symbol. Option C ($6A$) refers to the group number.

Answer:

D. 8