<span>Density can be calculated and found by dividing the sample's mass by its volume. D=m/v</span>
Via the half-life equation:

Where the time elapse is 11,460 year and the half-life is 5,730 years.

Therefore after 11,460 years the amount of carbon-14 is one fourth (1/4) of the original amount.
The plant that is closest to the sun is murcury. Then it is venus, then earth, and then mars. Then it is jupiter, then saturn, then uranus, then neptune.