Evidence Explain the sudden decrease in,
density when water is at 0°C as shown on
the graph.

Explanation:

The density of pure water ice at 0°C is 0.9168 g/ml, nearly 9% lighter than liquid water at 0°C, which has a density of 0.99987 g/ml 14. ... This drop in density occurs because the hydrogen bonds in water create an open hexagonal lattice, leaving space between the molecules 42.

b. acid is the correct answer @jayxboof all social media

acid : acids are those which accepts an electron-pairs.

base : bases are those which donates ab electron-pairs.

alkali : it is a base that dissolves in water. it is basically a base and the ph greater than 7.

hydroxide ion : it is a poly-atomic ion which is negatively charged.