The answer would be D. This is because you cross-cross the charges.
From the periodic table you get the atomic masses of each element.
These are the values that I have in my periodic table (use those numbers of your periodic table if your teache gave you a specific one)
Na: 23 g/mol
O: 16 g/mol
H: 1 g/mol
C: 12 g/mol
Ca: 40 g/mol
S: 32 g/mol
Mg: 24 g/mol
P: 31 g/mol
Now I will do some examples and you do the others:
1) NaOH: 1 atom of Na * 23 g/mol + 1 atom of O * 16 g/mol + 1 atom of H * 1 g/mol
=> 1*23g/mol + 1*16g/mol + 1*1g/mol = 40 g/mol
2) H2O
=> 2 atoms of H * 1 g/mol + 1 atom of O * 16 g/mol = 2*1g/mol + 1*16g/mol = 18 g/mol
3) Glucose: C6H12O6
6*12 g/mol + 12 * 1g/mol + 6*16 g/mol = 72g/mol + 12g/mol + 96 g/mol = 180 g/mol
4) CaSO4:
1*40 g/mol + 1*32g/mol + 4*16g/mol = 136 g/mol
Now you only have to do the last one by your own.
Natural, Organic & Manmade Fibers. after flame is out there is a soft gray ash!
The molecular formula:
The molecular formula is N₂O₄.