1.a noble gas in period 2 2.an element that does not belong to any family
3.a transition metal in period 5
4.a halogen
5.an alkaline carth metal
6.a metalloid in period 3
7.an alkali mctal in period 4
8.a nonmetal in group 5A
9.a metal in period 7
10.a metalloid in group 5A

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation:

the product of the pressure and volume is also constant