There are two isotopes of hydrogen commonly found in nature. hydrogen-1 which has an atomic mass of 1.007751 amu and hydrogen-2 which has an atomic mass of 2.014741. which isotope of these two isotopes is the most abundant? hint: think about how the atomic mass of the element hydrogen is calculated.

The H-1 isotope of hydrogen atom is a most abundant isotope.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

....(1)

Let the fractional abundance of H-1 isotope be 'x'. So, fractional abundance of H-2 isotope will be '1 - x'

For H-1 isotope:

Mass of H-1 isotope = 1.007751 amu

Fractional abundance of H-1 isotope = x

For H-2 isotope:

Mass of H-2 isotope = 2.014741 amu

Fractional abundance of H-2 isotope = 1-x

Average atomic mass of hydrogen = 1.008 amu

x = 0.9998

Fractional abundance of H-1 = x =  0.9998

Percentage of H-1 isotope = 0.9998 = 99.98%

Fractional abundance of H-2 = 1-x = 1 - 0.9998  = 0.0002

Percentage of H-2 isotope = 0.0002 = 0.02%

The H-1 isotope of hydrogen atom is a most abundant isotope.

SEE EXPLANATION

Explanation:

A)

1) The balanced  chemical reaction is;

Fe2O3 + 3H2O> 2Fe(OH)3

2) C12H22O11> 12 C + 11H2O

B)  1 is a combination reaction

     2 is a decomposition reaction

C) The molar mass of NH3 is 14 + 3(1) = 17 g/mol

Percentage composition of N = 14/17 * 100/1 = 82. 4 %

D) 1 mole of O2 contains 6.02 * 10^23 particles

E) For (NH4)3 PO4

We have 3(14 + 4(1)) + 31 + 4(16) = 149 g/mol

F) 1 mole of CaCO3 contains 100g of CaCO3

1.25 moles of CaCO3 contains 1.25 * 100/1 = 125 g of CaCO3