Abeaker contains a mixture of sand and small pebbles. what kind of mixture is this?

A heterogeneous mixture have compounds that remain separate in the sample.

Heterogeneous mixture is not uniform in composition (in this mixture different sand and small pebbles), but proportions of its components (in this mixture particles of different colors and size) vary throughout the sample.

the answer is 1 i believe

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.