Elements and Compounds
please help me

Question 1:

An element is a pure substance which cannot be broken down by chemical means.

Question 2:

A molecule is a group or cluster of two or more atoms held together by chemical bonds. A compound is a substance or material which is formed by two or more different types of elements which are combined chemically in a fixed proportion.

Question 3:

Electrons, Protons and Neutrons

Question 4:

Dmitri Mendeleev in 1869 developed the periodic table.

answer: if she breaths she a thho

explanation:

emerging idea only occurs as a raw idea that could appear out of nowhere. meanwhile, to reach scientific consensus , that idea must be structured and tested over and over again through various experiments. the scientific consensus transforms the raw idea into idea that is more reliable through the process of scientific elimination.