Option 4. ratio of electrons to protons
Isotope that has atomic number of 82 is stable. An element that has an atomic number ∠82 more stable except Tc and Pm. Also there is the concept that isotopes consisting a combination of even-even,even-odd,odd-even, and odd-odd are all stable. Many isotopes with no magic numbers of nucleons are stable
Answer:
I think C
Explanation:
because hydrogen on the right side only have two while on the left side it have 4
Answer:
6.25% of the original amount
Explanation:
half-life means that half is gone for every certain period of time. Because the half life is 1 month, only half of the 'radionulide' is left every month.
after 1 month= 50%
after 2 months= 25%
after 3 months= 12.5%
after 4 months= 6.25%
