The true answer is: It's conserved because the total number of H atoms on each side is 12.
the first two answer is wrong because it's conserved not as mentioned, It's not conserved.
and the last one also wrong because the total number of O atoms are equal at the two sides but not equal 2.
Answer: 1.348 ×10^23 atoms
Explanation:
Given that volume = 1.00L
At standard condition, the volume of a gas is 22.4L/mol (at S.T.P)
Volume = mole /volume at STP
1 = mole/22.4
Mole= 22.4mol.
Also
Mole = number of atoms /Avogradro constant
Where avogrado's constant = 6.02×10²³
22.4 = number of atoms/6.02×10²³
Number of atoms = 1.348×10^25atoms
Argon has 18 protons which identifies the element and is in group Noble Gases which has 8 valence electrons.