Describe why scientists changed the calculation of atomic mass from being based on hydrogen to oxygen and finally to carbon.

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante

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.

it's 3.2 on edge, i just took the test.