Answer:

Explanation:
The first step is:

Second step is:

Multiplying second step by 2, and adding both the steps, we get that:

Cancelling common species, we get that:

Answer:
must be either a gas or liquid
Answer:
can we see the type that is shown?
Hydrogen gas(H2) has a molar mass of 2 g. Molar mass of a substance is defined as the mass of 1 mole of that substance. And by 1 mole it is meant a collection of 6.022*10^23 particles of that substance.
So number of moles of H2 are 0.5 in this case. And thus it means there are (6.022*10^23)*0.5 particles( here they are molecules) in 1g of H2.