Krypton is the least metallic. Because it is a noble gas. The elements go from left to right in order of most to least metallic. Krypton is the farthest right out of all of the elements you listed.
Water breaks down into hydrogen and oxygen: It is a decomposition reaction as a single substance decomposes to give two products.
Leaves make starch using chlorophyll and carbon dioxide: Synthesis reaction: as the synthesis reaction involves two or more than two reactants which join together to result into a single main product along with the formation of simple by products.
Food burns in oxygen gas and releases a lot of energy: Combustion: Combustion process involves the use of oxygen to give products along with release of energy.
Adding vinegar (acid) to baking soda (alkali) gives a product that is neither acidic nor alkaline: Neutralization: acetic acid in vinegar reacts with soda (base) to give salt (neutral) and .
Answer:
pie chart as it shows the whole
I know one is transformed, not sure about another