What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
H2O is a compound because its a main constitute of earths hydrosphere
I think its 2-, it gained 2 electrons.
Explanation:
2H2 + O2 = 2H2O
2mol. 1mol. 2mol
2mol reacts with 1mol
13mol reacts with x
x=<u>13mol</u><u> </u><u>×</u><u> </u><u>1mol</u>
<u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u> </u><u>2mol</u>
x= <u>13mol</u>
<u> </u><u> </u><u> </u><u> </u><u> </u><u> </u>2mol
x= 6.5mol of oxygen