The half-life of carbon-14 is 5730 years. Dating organic material by looking for C-14 can't be accurately done after 50000years. Suppose a fossilized tree branch originally contained 4.30grams of C-14. How much C-14 would be left after 50000 years

answer; protein;

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.