It is protected by a mucus layer formed on the surface regularly that ressist ph values.If it isn't formed our body will eat itself.
Answer:
So, you're dealing with a sample of cobalt-60. You know that cobalt-60 has a nuclear half-life of
5.30
years, and are interested in finding how many grams of the sample would remain after
1.00
year and
10.0
years, respectively.
A radioactive isotope's half-life tells you how much time is needed for an initial sample to be halved.
If you start with an initial sample
A
0
, then you can say that you will be left with
A
0
2
→
after one half-life passes;
A
0
2
⋅
1
2
=
A
0
4
→
after two half-lives pass;
A
0
4
⋅
1
2
=
A
0
8
→
after three half-lives pass;
A
0
8
⋅
1
2
=
A
0
16
→
after four half-lives pass;
⋮
Explanation:
now i know the answer
<span>nuclear symbol consists of three parts: 1. the symbol of the
element; 2. the atomic number of the element;3. the mass of the element. for
the above problem, the symbol for potassium is k. it's atomic number is 40. the
number of protons is 19. so we denote this in the following nuclear symbol; 40
k 19</span>
