the quality or state of the chemical substance that has a pH values below 7:
举一反三
- A pure substance always has the same physical and chemical properties and is either an element or a compound.。（ ）
- A chemical is any aspect of a substance which is only seen by means of a chemical reaction (反应).
- With a chemical r______, a new substance can form.
- When<br/>the substance is measured by atomic absorption spectrophotometry, the<br/>state of the substance is ( ) A: Solid<br/>state B: Liquid C: Vapor<br/>state D: Supercritical<br/>state
- The change in which a new substance is formed calls a chemical change（）.