The radioactive decay obeys first order kinetics
the rate law expression for radioactive decay is
![ln\frac{[A_{0}]}{[A_{t}]}=kt](https://tex.z-dn.net/?f=ln%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D%3Dkt)
Where
A0 = initial concentration
At = concentration after time "t"
t = time
k = rate constant
For first order reaction the relation between rate constant and half life is:

Let us calculate k
k = 0.693 / 72 = 0.009625 years⁻¹
Given
At = 0.25 A0

time = 144 years
So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**
Simply two half lives
It would 3 because if you read it tells you the answer
Answer:add acid
Explanation:
Methyl orange is red in acid and yellow in base. When added to distilled water and the colour turns yellow, it means it is in its anion form. The equilibrium can be shifted towards the acid form (HMO) by adding acid. The acid will protonate the indicator shifting the position of equilibrium towards the acid side and the solution turns red.
Answer:
100N
Explanation:
Given parameters:
Mass of the bowling ball = 20kg
Acceleration = 5m/s²
Unknown:
Amount of force applied = ?
Solution:
To solve this problem, we apply newton's second law of motion.
Force = mass x acceleration
Now insert the parameters and solve;
Force = 20 x 5 = 100N