Describe the difference between elements and compounds and atoms and molecules

element are made up of the same type of atom, while a molecule is made up of 2 or more atoms of the same species. a compound is made up of 2 or more different types of atoms of different species

Explanation:

essentialy, elements and compounds are made both of atoms, except elements are made of one type of atom, while compounds are made up of 2 or more types of atoms.

an atom is the smallest building block of matter while molecules consist of one or more atoms bonded together

Compounds are made of two or more atoms of different elements, such as water (H2O) and methane (CH4). Atoms are not drawn to scale. Molecules of compounds have atoms of two or more different elements. For example, water (H2O) has three atoms, two hydrogen (H) atoms and one oxygen (O) atom.

8 carbon atoms forming single bonds with 18 hydrogen atoms; a triple bond exists between the third and fourth carbon atom from the right

explanation:

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.