Question

modeling atoms and molecules
how can you make models of simple molecules and compounds?
background
each element is made of only one kind of atom. the atoms of different elements are different. a molecule is made of two or more atoms joined together. compounds are molecules made of two or more different elements. in this activity, you will model compounds by combining objects that represent different elements.
materials (per pair)

• foam balls
• toothpicks
• colored markers

safety
be sure to follow all safety procedures provided by your teacher. find more information about the safety icons in the safety section.
procedure

1. examine the objects supplied by your teacher. each styrofoam ball should represent one kind of atom. use the colored markers to create four kinds of “atoms.”
2. assign a symbol to each of the four kinds of atoms. for example, one can be hydrogen (h) and another can be oxygen (o).
3. assemble three different molecules, including water, from the four kinds of atoms. use the symbols you assigned to write a formula for each of the molecules you construct.

think it over

1. develop models how did you represent the four kinds of atoms? what represents a chemical bond?
2. apply concepts of the three molecules you assembled, how many were compounds?

Explanation:

Step1: Identify atom - representation

Used colored - marked foam balls to represent four kinds of atoms.

Step2: Identify bond - representation

Toothpicks represent chemical bonds as they join the foam - ball “atoms” together.

Step3: Determine number of compounds

Since a compound is a molecule made of two or more different elements, and water (H₂O) is a compound. Assuming the other two molecules also meet the criteria of being made of different elements, all three molecules are compounds.

Answer:

1. The four kinds of atoms were represented by colored - marked foam balls. Toothpicks represent a chemical bond.
2. 3