Question

1. which of the following can be broken down by physical means. a. element b. mixture c. compound d. solution 4. methane (ch4) is an example of a/an _________. a. element b. compound c. mixture d. all of the above

Explanation:

For question 3, elements are pure substances that cannot be broken down by physical means. Compounds are made of two or more elements chemically combined and require chemical means for decomposition. Mixtures (including solutions) are combinations of substances that can be separated by physical means like filtration, evaporation etc.
For question 4, methane ($CH_4$) is composed of carbon and hydrogen atoms chemically bonded together, so it is a compound. Elements are made of a single - type of atom, and it is not a mixture as it has a definite chemical formula.

Answer:

1. B. Mixture
2. B. Compound