B because....................
Answer:
b) coefficient
Explanation:
Refer to this example:
CH4 +2 O2 → CO2+ 2 H2O
2 is used as a coefficient in this chemical equation.
Answer:
<u>2 years</u> to decay to a mass of 50g.
Explanation:
given:
100g of substance with a half life of 2 years
to a mass of 50g
Half life is the amount of time taken by a radioactive material to decay to half of its original value.
ln 2 0.693
Half life T1/2 = ---------- = -----------
λ λ
where λ = rate constant
The initial amount of 100 grams is decaying to a mass of 50 grams is half of its initial value.
Therefore, it will take 2 years for the decay.
C. The water molecules must gain kinetic energy.
