To identify a substance, chemists observe two distinct types of , physical and chemical, which are related to physical and chemical that matters undergoes.
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).
- The change in which a new substance is formed calls a chemical change（）.
- A chemical _______ is any aspect of a substance which is only seen by means of a chemical reaction (反应). A: queries B: property C: obstacles D: margins
- ( ) assessments must take place to determine exactly what the<br/>patient's nutritional requirements are. A: Physical and chemical B: Biochemical and physical C: Psychological and clinical D: Clinical and biochemical