I mostly believe in between D and B beacuse K3po4 and caco3 is not an element equation
Answer:
Carbon - 13
Explanation:
For most of the elements other than that of hydrogen, the isotopes are named for the mass number.
Example : Carbon atoms with 6 neutrons have mass number of 12 ( as
), so they are known as carbon-12.
Given that:
Protons = 6
Neutrons = 7
Mass = 6 + 7 = 13
So the name is Carbon - 13 . The symbol is 
Carbon has 4 valence electrons, oxygen has 6
The appropriate response is Mg2+. It has the smallest radius the would mean the littlest separation from it's the furthest shell to the core
Since magnesium has one less shell that calcium, Mg would have a little nuclear range. Besides, a particle of a component will have a little nuclear sweep than it's molecule be utilized as a part of its particle frame it has lost a shell