The diagram shows a sound wave. D
А
to
B
с
E
What part of the wave will change if the pitch of the sound is changed?
O A. the distance between A and C
O B. the distance between B and E
O
C. the distance between C and D
O
D. the distance between D and E

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter  

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.

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)