Question

calcium
slide 4:two examples (visual models) of compounds are given ( water - h₂o, on the left and co₂,carbon dioxide on the right). what is one difference you notice with the visual model in slide 2? ( in terms of combination of atoms/elements)
h₂o - how many types of colored spheres? -
co₂- how many types of colored spheres?
slide 6: what is the difference between an element and a compound?
element-

compound-

Explanation:

For $H_2O$, there are 2 types of elements (hydrogen and oxygen), so 2 types of colored spheres in visual model. For $CO_2$, there are 2 types of elements (carbon and oxygen), so 2 types of colored spheres. An element is a pure substance made of only one type of atom. A compound is a pure - substance made of two or more different types of elements chemically combined.

Answer:

$H_2O$: 2 types of colored spheres
$CO_2$: 2 types of colored spheres
Element: Made of only one type of atom
Compound: Made of two or more different types of elements chemically combined