Chemical Formulas and Models

Introduction to Chemical Formulas

What is a Chemical Formula?

• A chemical formula shows the types and numbers of atoms in a substance.

• Example: H₂O (water) gas 2 hydrogen atoms and 1 oxygen atom
  

Why Chemical Formulas Are Important

Why do We Use Chemical Formulas?

• They help scientists understand and communicate the composition of substances.

• They are used to create and analyze materials in chemistry

Introduction to Ball-and-Stick Models

What is a Ball-and-Stick Model?

• a ball-and-stick model shows how atoms are bonded together in a molecule.

• Balls represent atoms, and sticks represent bonds between them.

How to Read a Ball-and-Stick Model

Reading a Ball and Stick Model

• Identify the different colored balls representing different types of atoms

• Notice how the sticks (bonds) connect the balls to show the molecule's structure.

Comparing Chemical Formulas and Ball-and-Stick Models

Chemical Formulas vs. Ball-and-Stick Models

• Chemical Formulas show the number of each type of atom

• Ball-and-Stick models show how atoms are connected and arranged in space.

Multiple Choice

Is this a chemical formula or a ball and stick model?

• chemical formula

• ball and stick model

• none of the above

Multiple Choice

What information does a chemical formula provide about a substance?

• the color of the substance

• the types and numbers of atoms

• the weight of the substance

• the texture of the substance

Draw

Draw a ball and stick model for H₂O

Multiple Choice

Which of the following is true about the sticks in ball-and stick-models?

• they represent different types of atoms

• the represent bonds between atoms

• they show the color of the atoms

• they show the weight of the atoms

Open Ended

Name one difference between a chemical formula and a ball-and-stick model.