What is the Name of the Physical Change that occurs in each of the Following Instances? a. Oxygen is cooled from -150°C to -200°C

b. Iron is cooled from 1600°C to 1500°C

c. Mercury is heated from -130°C to -100°C

i have no clue hope you find the answer

catya your not at all which answer i've seen you do this on another question!

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.