**Definitions:**

**Atomic Mass Unit** (abbreviations: **amu, or u**): also known as dalton (symbol: Da), is a standard unit of mass that used on an atomic or molecular scale (atomic mass). One unified atomic mass unit is about the mass of one nucleon (either a single proton or neutron) and equivalent to 1 g/mol.

**Kilogram** (abbreviations: **kg, or kgm**): is a SI (metric) system unit of mass (IPK, also known as "Le Grand K" or "Big K") and equivalent to 1/1000 of one gram. Where, at the temperature of melting ice, one gram is the absolute weight of a volume equal to the hundredth part of a metre cube of pure water.

## How to Convert Atomic Mass Units to Kilograms

*Example: How many kilograms are equivalent to 23.99 atomic mass units?*

As;

1 atomic mass units = 1.66E-27 kilograms

23.99 atomic mass units = Y kilograms

Assuming Y is the answer, and by criss-cross principle;

Y equals 23.99 times 1.66E-27 over 1

(i.e.) Y = 23.99 * 1.66E-27 / 1 = 3.98234E-26 kilograms

Answer is: 3.98234E-26 kilograms are equivalent to 23.99 atomic mass units.

*Practice Question: Convert the following units into kg:*

N.B.: After working out the answer to each of the next questions, click adjacent button to see the correct answer.

( i ) 67.62 amu

( ii ) 47.21 amu

( iii ) 85.11 amu