If anyone will do this answer correct
i will mark you as brainliest.
question no. 4 and 5.

Explanation for part 4 :

Compound : It is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.

For example : The carbon tetrachloride is made from atoms of different elements (carbon and chlorine) combined together in a fixed ratio by mass.

The carbon dioxide is made from atoms of different elements (carbon and oxygen) combined together in a fixed ratio by mass.

Element : It is a pure substance which is composed of atoms of similar elements.

For example : The molecule of hydrogen element is made from atoms of similar element (hydrogen).

The molecule of nitrogen element is made from atoms of similar element (nitrogen).

Explanation for part 5 :

Atom : It is a smallest unit of matter which can not be further divide.

When the atoms have equal number of protons (which is positively charged) and electrons (which is negatively charged) then the atoms are electrically neutral.

When an atom gains or lose one or more electrons then it becomes an ion. The ion can be anion by gaining an electron and can be cation by losing an electron.

Hence, the atoms are electrically neutral when an atom have equal number of protons and electrons.

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.

i think it's letter a.