Answer:
13 years
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
Where;
t1/12 = half-life of Cobalt-60 = 5.3 years
t = time taken = the unknown
No = mass of radioactive material originally present = 5.2 g
N = mass of radioactive material at time t = 0.95 g
Substituting values;
0.693/5.3 = 2.303/t log (5.2/0.95)
0.131 = 2.303/t(0.738)
0.131 = 1.6996/t
t = 1.6996/0.131
t = 12.97 years
t = 13 years(to the nearest whole number)
Answer:
they have differnet properties that repeat across the next period
Explanation:
Not sure. How to answer this question.Look it up
Answer:
Matter is the "stuff" that makes up the universe everything that takes up space and has mass is matter.
All matter is made up of atoms, which are in turn made up of protons, neutrons and electrons
The ________ orbital is degenerate with 5py in a many-electron atom.
<h2>
5px is the correct answer</h2>
