Mrs. Johnston heated 5 grams of sugar. The sugar first looked shiny, and then it melted and became dark brown. Finally, all that was left
was a black, shiny residue. She then heated 5 grams of sand in the
same way. The sand's appearance did not change.
What explains these results?

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.

answerca air mass;