Which elements are found in all living things? 30 POINTS!!
carbon, oxygen, potassium, calcium, nitrogen, sulfur
hydrogen, phosphorus, oxygen, calcium, nitrogen, sulfur
carbon, hydrogen, phosphorus, oxygen, nitrogen, sulfur
hydrogen, oxygen, potassium, calcium, nitrogen, sodium

The correct option is C

Oxygen

Carbon

Hydrogen

Nitrogen  

Sulfur

Phosphorus

Explanation:

Oxygen is considered to be the most abundant element to be found in the living cells. Usually, a living cell is made up of 65% oxygen.

Carbon is the element which forms the basis for life for all organisms which can be seen on the planet Earth.

Hydrogen combines with oxygen to form water which makes up 65 percent of the human body.

Nitrogen is an active constituent of molecules such as proteins which are of utter importance to an organism.

Phosphorus is present in the form of phospholipid layer which is an active constituent of the cell membranes.

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.