Answer:
a.labeling food with an ingredient list to inform consumers
Explanation:
4. A
because PbCl2 is an ionic compound and it's solid, so it's a substance.
It cannot be mixture, because it's a pure molecule.
5. D
despite that both substances are gases, colorless they are different molecules, so they should have different either chemical and physical properties
6. C
this substance made from W atoms and others are made from molecules
Characteristic properties are used because the sample size and the shape of the substance does not matter.
Answer: varriable
Explanation:meaning one element, feature or factor able to change
