The type of a bond in which two atoms share their electrons is called the covalent bond. A famous example of this is the bond between two hydrogen atoms.
Explanation:
sorry I am class ninthonly
It would be:
2H2 + O2 -> 2H2O
<u>Answer:</u> The mass of iron (II) oxide that must be used in the reaction is 30.37
<u>Explanation:</u>
The given chemical reaction follows:

By Stoichiometry of the reaction:
When 635 kJ of energy is released, 6 moles of iron (II) oxide is reacted.
So, when 44.7 kJ of energy is released,
of iron (II) oxide is reacted.
Now, calculating the mass of iron (II) oxide by using the equation:

Moles of iron (II) oxide = 0.423 moles
Molar mass of iron (II) oxide = 71.8 g/mol
Putting values in above equation, we get:

Hence, the mass of iron (II) oxide that must be used in the reaction is 30.37
Only when there is no product that is when a chemical reaction has not occured