If a sample of C-14 initially contains 1.2 mmol of C-14, how many millimoles will be left after 2285 years?

The amount of millimoles left after 2285 years is 0.910 millimoles

Explanation:

The half life of  a substance is the time require for a radioactive decaying substance to have decayed int half of its initial quantity. Half life is used to different types or forms of decay such as in nuclear physics, to describe the time of decay of unstable atoms and in medicine to define a drugs half-life

To  solve this, we are required to state the hlf life of C-14 which is 5,730 years

Hence the formula for calculating half life is  

∴ = 0.910 millimoles will be left after 2285 years

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.