Membranes are barriers and “gatekeepers”, they only let certain molecules pass through them.
they also transport nutrients to the cell
The percentage composition of this compound : 40%Ca, 12%C and 48%O
<h3>Further explanation</h3>
Given
20.0 g of calcium,
6.0 g of carbon,
and 24.0 g of oxygen.
Required
The percentage composition
Solution
Total mass of compound :
=mass calcium + mass carbon + mass oxygen
=20 g + 6 g + 24 g
=50 g
Percentage composition :



1 mole C6H12O6 -------------- 180.15 g
? moles C6H12O6 ------------ 523.46 g
523.46 x 1 / 180.15 => <span>2.905 moles</span>
Could you retype this please? I can 100% answer your question but I think you accidentally input the questions wrong