Answer:
Barium and Calcium
Explanation:
When heated with chlorine,
Both calcium and barium are able to form ionic bonds.
Hydrogen can only form bonds that are partial positive. It is not strong enough to be considered an ionic bond.
Silicon forms strong covalent with chlorine, called silicon tetrachloride. The structure is in diamond form which requires a lot of heat energy to break the bonds are way more than energy needed to break the bonds between calcium chloride.
Krypton is an inert element which does not form bonds with any elements under standard conditions
Answer:
Basing on explanations below;
1. Endothermic reactions have a positive enthalpy while Exothermic reactions have a negative enthalpy.
2. Endothermic reactions take place in high temperatures while Exothermic reactions take place in low temperatures.
On a mountainside
in a lake
on a sandbar
in a sand dune
