Question

Jenny wanted to make 3 molecules of a substance made with aluminum and oxygen. How many aluminum and oxygen atoms will she need

Answer 1

D. 6 aluminum; 9 oxygen

Answer 2

Answer is: She will need 6 aluminium and 9 oxygen atoms.

Substance made from aluminium and oxygen is aluminium oxide (Al₂O₃).

On molecule of aluminium oxide has two aluminium atomsa and three oxygen atoms.

So three molecules of aluminium oxide will have:

1) 3 · 2Al = 6Al; six aluminium atoms.

2) 3 · 3O = 9O; nine oxygen atoms.