i think it is 8. I might be wrong.
Your question is incomplete. However, I found a similar problem fromanother website as shown in the attached picture.
To solve this problem, you must know that at STP, the volume for any gas is 22.4 L/mol. So,
Moles O₂: 156.8 mL * 1 L/1000 mL* 1 mol/22.4 L = 0.007 moles
Mass calcium: 0.007 mol O₂ * 2 mol Ca/1 mol O₂ * 40 g/mol Ca =
<em> 0.56 g Ca</em>
I think it's call a magnet
Answer:
for instance :
water , H²O , and hydrogen peroxide . H²O² , are alike
in that their respective molecules are composed of hydrogen and oxygen atomd . hope its helpful . Good luck :)