Question

3.011 x10^23 atoms of oxygen

Answer 1

$for \: 6.023 \times {10}^{23}has \: one \: mole \: of \: oxygen \: \: for \: \\ 3.011 \times {10}^{23} half \: mole \: of \: oxgen \: atoms \:$

Answer 2

6.023×10^23atom=16g
1atom=16/6.023×10^23
3.011×10^23=16/6.023×10^23×3.011×10^23=3011/376(approax)atom