Answer:
Carboxylic acid
A carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO₂H, with R referring to the alkyl, alkenyl, aryl, or other group. Carboxylic acids occur widely. Important examples include the amino acids and fatty acids.
Answer: when two elements combine, A and B, the ratio of the weight of B combining with A is always a whole number
Explanation:
A hypothesis is a prediction of what you believe to be true.
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