Answer:
mNaCl = mNa + mCl
mNa = 20g
mCl = mCl2/2 = 30/2 = 15g
mNaCl= 20+15 = 35g
2) chemical
3) chemical
4) physical
5)chemical
6)chemical
7)physical
8)physical
9)physical / chemical
100% sure
when two heavy hydrogens combine to for helium , it results in the formation of energy, and a neutron, along with the helium atom
Assume there is 100g of the substance at first