Metals are to the left of the zig-zag, nonmetals are to the right, and metalloids lie on/beside the line.
It is water soluble so is also soluble in aqueous solutions of NaOH or NaHCO3.
So,
With addition, we the last digit we keep will be the one which is known for both individual values.
We know 2.13 to the hundredths, but we only know 1 to the ones. Therefore, we will round off in the ones place.
2.13 + 1 = 3.13 (unrounded)
= 3 (rounded)
Hope this helps!
Answer:

one atom of an element = 6.02 \times {10}^{23} atom
The mass of one atom of sulphur = 32g
The mass of one atom of aluminium = 27g
so one atom of aluminium = 6.02 \times {10}^{23}
27g of AL = 6.02 \times {10}^{23} atom
2.70g of AL = X atoms
Then you cross multiply ........
and get the answer
.