Radioactive decay is expressed by the following formula:
N₀ is the initial number of undecayed atoms.
Nt is the number of undecayed atoms remaining after time t
λ is the decay constant.
The relationship between λ and the half life time t1/2 is:
λ =
= 0.693 / 5.27 = 0.1315
Taking natural logs for both sides of the decay expression:
ln Nt = ln N₀ - λ t
ln Nt = ln 199 - (0.1315 x 20)
= 5.293 - 2.63 = 2.66
From which:
Nt = 14.29 g
Correct answer is option D becauce C12 and C14 are isotopes.they have same atomic numbers but dif atomic masses.
Answer:
umm.. B. a base that generates a lot of hydroxide ions in water.
Answer:
Brainstorm with colleagues
Explanation:
So you can have different ideas.
Answer:
C) The object accelerates across the surface.
Explanation: