What you were given is the balanced chemical equation
Mg(OH)2 is the correct chemical formula because it takes two Hydroxide ions to bond with Magnesium normally it would be written with a subscript number 2 rather than the parenthesis and number 2
A hydrogen atom is an atom of the chemical element hydrogen. The electrically neutral atom contains a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force. Atomic hydrogen constitutes about 75% of the baryonic mass of the universe.
Answer: The person lived for 80.66 years.
Explanation:
Heart beat of the person = 73 beat /min
Number of total heart beats = 
Life span of the person : 
1 year =525600 mins
Life span = 
The person lived for 80.66 years.