Question

The density of nitrogen is `0.00125 g"/"cm^3`. What is the density expressed in scientific notation?

Answer 1

`1.25xx10^(-3) "g/cm"^3"`

Explanation:

The value is a decimal, meaning that `x` in `10^x`, must be a negative number.

If `10^0 = 1"`, then `0.00125xx10^0 = 0.00125xx1 = 0.00125`,

the value of `x` is the number of zeros in front of the first non-zero number,

In `color(blue)((0.00))125`, there are `color(blue)(3)` zeros.
`0.00125= 1.25xx10^(-3)`.

Answer 2

`1.25xx10^(-3)" g/cm"^3`

Explanation:

`"a number expressed in scientific notation is of the form"`

`color(red)(bar(ul(|color(white)(2/2)color(black)(axx10^n)color(white)(2/2)|)))`

`"where " 1<= a< 10" and n is an integer"`

`"write " 0.00125" as a number between 1 and 10"`

`"that is " 1.25`

`"to find n we require the number of decimal places the"`
`"decimal point has to move to be back where it was"`

`"3 places to the left denoted by " 10^(-3)`

`rArr0.00125=1.25xx10^(-3)" g/cm"^3`