Wow, now this one is a hard one, took me quite a while to figure it out but here it is:

The abundances of the two isotopes is:
Antimony-121 = 57.2%
Antimony-123 = 42.8%
Answer: electron–negative, neutron–neutral, proton–positive
Explanation:
Atom is made up of three subatomic particles named protons, neutrons and electrons. Both protons and neutrons are found inside the nucleus of the atom, while electrons are found outside the nucleus of the atom. The charge distribution are as follows:
- The proton carry a positive charge
- The neutron carry no electric charge (i.e electrically neutral)
- The electron carry a negative charge
<h3>
Answer:</h3>
#1. 50 g
#2. 25 g
#3. 4 half lives
<h3>
Explanation:</h3>
<u>We are given;</u>
- Original mass of a radioisotope as 100 g
- Half life of the radioisotope as 10 years
We need to answer the questions:
#a. Mass remaining after 10 years
Using the formula;
Remaining mass = Original mass × 0.5^n , where n is the number of lives.
In this case, since the half life is 10 years then n is 1
Therefore;
Remaining mass = 100 g × 0.5^1
= 50 g
Therefore, 50 g of the isotope will remain after 10 years
#b. Mass of the isotope that will remain after 20 years
Remember the formula;
Remaining mass = Original mass × 0.5^n
n = Time ÷ half life
n = 20 years ÷ 10 years
= 2
Therefore;
Remaining mass = 100 g × 0.5^2
= 25 g
Thus, 25 g of the isotope will be left after 20 years
#3. Number of half lives in 40 years
1 half life = 10 years
But; n = time ÷ half life
= 40 years ÷ 10 years
= 4
Thus, the number of half lives in 40 years is 4.
Answer: C. Electrons from the cathode combine with hydrogen cations through reduction reactions.
Explanation: 100% on edg 2021 quiz
The answer is gas hope this helps