The answer is maritime air masses
Answer: burning paper
Explanation:
The paper burns in air to form smoke and ash. which makes it a chemical change.
The dispersed particles of a colloid exhibit brownian motion, in which they move in a chaotic manner without a discernible pattern. The brownian motion is the erratic random motion of particles that are suspended in a fluid which results to the collision of molecules moving fast in the fluid they are in.
Half life is the time taken by a radioactive isotope to decay by half its original mass.
The original mass is 200 g
Time taken is 60 hours
Final mass is 25 g
Therefore;
Final mass = Original mass × (1/2)^n; where n is the number of half lives.
25 = 200 (1/2)^n
1/8 = (1/2)^n
n = 3
Three half lives = 60 hours
1 half lives = 20 hours
Therefore; the half life of the radioactive nucleus is 20 hours