Answer:
1 mole of lithium is 7 grams. we know this from it's relative molecular mass.
if 1 mole is 7 grams then x moles is 0.56 grams
we can equate them by saying (1/x)=(7/0.56)
after cross multiplying, we get 7x=0.56, x will be equals to 0.56/7
x=0.08 grams
