Chapter 1: Matter and Energy

Section 2: Matter is made up of atoms

Overview

Review: Matter is anything that has mass and volume.

Big Idea: Matter is made of particles too small to see. Everything that has mass and takes up space is matter.

Objective: to learn about what atoms and molecules are and how they move.

ReviewQ) What is matter?

A) Matter is anything that has mass and takes up space

Q) What is mass?

A) Mass is the amount of matter in an object.

Q) What is Volume?

A) Volume is the amount of space an object takes up

Q) How do we measure volume?

A) By formula or water displacement

Atoms are extremely small

All matter is made up of atoms, which are so small that a teaspoon full of water has approximately 5 x 1023 atoms.

500,000,000,000,000,000,000,000 atoms!

Atoms are extremely small

An atom has a radius of approximately 10-10 meters. Scientists have identified more than 100 kinds of atoms.

Atoms combine to form molecules. A molecule can be made from two or more of the same kind of atom or from two or more different kinds of atoms.

The diagram below shows the makeup of a water molecule and an ozone molecule.

Atoms and Molecules are always in motion

Atoms and molecules are always moving. You can see evidence of moving air molecules as they collide with dust or other particles in the air.

Atoms and Molecules are always in motion

You can see liquids move when you add a drop of food coloring to water. Even the atoms and molecules in a solid constantly vibrate.

The smallest basic unit of matter basic building blocks

A carbon atom a rock

A. An atom is the smallest basic unit of matter.

B. B. The idea of existence of atoms dates back to the fifth century B.C.

C. Today scientists know of more than 100 types of atoms.

Question: Can you see an individual atom? Why or why not?

Answer: No; They are too tiny to see even with strong microscopes

Two or more atoms bonded together water is made up of H and O

Water Molecule single hydrogen atom

A. Dust particles show that molecules in air are constantlymoving. B. Water molecules are also constantly moving, asshown by food coloring. C. Even molecules in solid objectsshake back and forth or twist.