Answer:
Phosphorus, chlorine and selenium.
Explanation:
If you look at a periodic table, you will notice that phosphorus, chlorine and selenium are all in groups 15-17. Elements in these groups are more likely to gain electrons then they are to lose them, thus making them more likely to form an anion.
This is because they want to fill their outer valence shell of electrons so that they can have a full octet and for groups 15-17 it’s easier to gain 1-3 electrons then it is to loose 5-7 electrons.
BaCO3=BaO+CO2
IS THE EQUATION REPLACE = WITH AN ARROW.
The correct answer is B. Low chemical reactivity
D is the correct answer... if u need in depth let me know