2. how do the structures of elements differ from those of compounds? 3. chemical formulas show the amounts…

Brief Explanations:

2. Elements are pure substances with only one - type of atom. Their structures are based on the number of protons, neutrons, and electrons in the atom. Compounds are made up of two or more different elements chemically combined in a fixed ratio. Their structures involve chemical bonds between different atoms.
3. Chemical formulas for elements show the symbol of the element, and for single - atom elements like Na (sodium), it represents one atom. For diatomic elements like O₂, it shows two atoms bonded together. Chemical formulas for compounds, like H₂O, indicate the types and ratios of elements present in the compound (2 hydrogen atoms and 1 oxygen atom).

Answer:

2. Elements have single - type atoms with their own atomic structures. Compounds have combinations of different atoms with chemical - bonded structures.
3. Element formulas show the element symbol or number of atoms of the same element. Compound formulas show types and ratios of different elements.