The mass of a hydrogen atom is 0.000 000 000 000 000 000 000 001 67 g.
To represent this very SMALL number in exponential notation, we will write a number between 1 and 10 multiplied by 10-n where n equals the number of places the decimal point was moved to the right. Notice the minus sign in the exponent.
If we write the mass of a hydrogen atom as
1.67 x 10-n
What is the value of n?