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
In order to form polymers, we need to chain molecules together. This involves making bonds between them.
Shifting H’s around doesn’t accomplish anything.
Forming more double bonds will have the opposite result, as it would make the molecules more stable and less likely to react with each other.
Adding oxygen to the molecule no longer makes it polybutene. That would likely result in the formation of some sort of ether, as hey would react to form a C-O-C Bond.
The only answer left is A. In order to form polyalkenes, we have to break a double bond so that it’s available to form more covalent bonds.
Hope this helps
C can be the only correct answer - 6.023 x 10^23 is the amount of molecules in a mol of an element. 4.5 x 6.023 x 10^23 can not equal anything but C.
4.5 x 6.023 x 10^23 = 2.71035 x 10^24
Option no. 2 subtracting the atomic number from the mass number
Example: Zn - 65 atomic weight or mass/mass number
30 atomic number
65-30 = 35 number of neutrons
