RAM and isotope abundance | hannahsatomuniverse

The relative atomic mass, Ar is the ration of the average mass of the atom to the unified atomic mass unit.

The atomic mass of the electron is 1/1836 amu ( atomic mass units)

The unified atomic mass refers to a non SI unt of mass. It makes up one twelfth of the mass of a carbon-12 atom (in its ground state)

1 amu/ 1 u = 1.6605402 x 10 kg

The unit expressed above is also applied to represent the masses of atomic particles.

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RAM (Relative Atomic Mass)

isotopic Abundance refers to the quantity of an isotope of an element which is found in nature.

Isotopic Abundance can also be refered to as " Natural Abundance:

Isotopic Abundance

There are three main steps involved in calculating isotope abundance

1) NOTE DOWN THE element's isotope and mass number.

2) Calculate the atomic mass of all of the isotopes

3) divide the calculated atomic mass quantity by 100.

CALCULATING RAM

Multiply the calculated atomic mass quanitity by the atomic mass of the isotope.

ADD the resultant values together. You now have the Relative atomic mass of the element

This is an example with the isotopes of Lithium

Lithium only has two naturally ocurring isotopes;

1.)

2.)

= 7.59 = 7.5 % 3.) 7.5/100 = 0.075

= 92.41 = 92.5 % 3.) 92.5/100 = 0.925

abundance is 0.075 %

abundance is 0.925 %

= 0.075 x 6.015223 =

= 0.925 x 7.016003 = 6.489802775

0.451141725

0.451141725 + 6.489802775 = 6.9409445

Li-7 is used to regulate the pH level of the coolant in the primary water circuit of pressurized water reactors.

In addition to this Li-7 is also used for the manufacture of the medical research for radioisotope Be-7.

Li-6 is used in thermonuclear weapons; it is due to this that exporting and using of Li-6 is regulated seriously.

In addition to this; Li-6 is also used in the manufacturing of the radioisotope H-3.

This radioisotope is applied in biochemistry for reasearch. (webelements.com)