Abiochemist studying breakdown of the insecticide ddt finds that it decomposes by a first order reaction with a half life of 12.0 years. how long does it take ddt in a soil sample to decompose from 413 ppbm to 10.0 ppbm (parts per billion by mass)?

64.4 years

Explanation:

The half-life (t1/2) for the first order breakdown of DDT is 12.0 years. The rate constant (k) is:

k = ln 2 / t1/2 = ln 2 / 12.0 y = 0.0578 y⁻¹

We can find the time (t) for an initial concentration A₀ = 413 ppbm to decrease to A(t) = 10.0 ppbm, using the following expression.

why is cellular respiration important for homeostasis?

it changes food into energy that the organism can use.

which of the following is most likely to happen if a cell is not able to divide?

the cell will not be replaced when it is damaged.

explanation: