PHYSICAL AND CHEMICAL CHANGES

Chapter 3 Lesson 1What is matter made of?

E.Q. – What is matter made of?

Standards: S5P1b Investigate how common

items have parts that are too small to be seen without magnification.

S5P2a Investigate physical changes by separating mixtures and manipulating paper (cutting, tearing, folding) to demonstrate examples of physical change.

Key vocabulary –

Atom – the smallest unit of an element that has the properties of that element.

Molecule – a group of two or more atoms that are joined chemically.

Element – a substance made of only one kind of atom.

Basic Properties of Matter

Matter is anything that has mass and takes up space. Some examples of matter include: your bed, the water in the ocean, and the air in your classroom.

Examples of things that are not matter include: sunlight and ideas. A light room doesn’t have more mass that a dark room. Ideas are also not matter because your brain doesn’t take up more space when you think hard.

Matter is made up of different properties.

Air is everywhere. It is matter because it takes up space. You can put different amounts of air into a container. You can’t see the particles, so they must be very small.

Other properties of matter include solubility, mass, and hardness. Some materials act differently when combined with water. Some materials are heavier than others.

Particles of Matter

A Greek thinker had an idea about matter over 2000 years ago. He said that all matter is made up of tiny particles, or bits. Different kinds of matter are made up of different kinds of particles.

Scientists have since learned that matter can be broken down into atoms. An atom is the smallest possible particle of a substance. You get molecules when two or more atoms join together.

Elements

Water is not an element because the smallest possible particle of water is a molecule made up of two different kinds of atoms – two hydrogen atoms and one oxygen atom.

Hydrogen and oxygen are elements. Elements are substances that are made up of just one kind of atom. Some examples of elements include: iron, gold, carbon, mercury, and silver.

Groups of Elements

Elements are grouped into categories: metals and nonmetals. Many metals are elements. However, not all metals are elements. For example, steel is a combination of two elements, iron and carbon. Most metals share many properties: shiny, malleable (can be easily changed or shaped), ductile (can be pulled into thin strands –wires).

Nonmetals are different from metals. Nonmetals are dull, can’t be pounded or stretched out. Most are brittle and don’t conduct electricity very well.

Noble gases are not metals nor are they nonmetals. They are different because they are colorless and odorless. Some of them can glow when electricity is added to them.