Target Goal: I can verify that an object is the sum of its parts. What is Matter Made Of? Target Goal: I can verify that an object is the sum of its parts.

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 Air is matter The particles that make up matter are too small for the eye to see Substances have properties such as solubility, mass, and hardness

Basic Properties of Matter Some particles are heavier or hold together more tightly The tiny particles that make up each substance are different

Particles of Matter More than 2000 years ago, a Greek thinker named Democritus had an idea about matter. Democritus said that all matter is made up of tiny particles, or bits. He said that different kinds of matter are made up of different kinds of particles. And he thought that these particles could not be broken down into smaller parts.

Challenge: Do you think he was right or wrong? Why?

Particles of Matter Democritus didn’t experiment or test his ideas in any way. Still, it turns out that he was right. We now know that matter can be broken down only so far. If you divide something smaller and smaller, you end up with an atom.

Particles of Matter Atoms and molecules are extremely small. They are too small to be seen even by a regular microscope because single atoms and molecules are too small to reflect light! There is no way to see an atom or molecule unless you use a special microscope.

Particles of Matter Democritus made up the word atom. It comes from a word that means “cannot be divided.” Think about a tank of oxygen. You can divide all the oxygen inside into smaller and smaller parts. But when you get to an oxygen atom, you have to stop. If you break it up further, it won’t be oxygen anymore.

Elements Scientists have identified 116 elements. Hydrogen, Oxygen, and Iron are all elements. Gold is also an element. What sort of things are made out of iron? What sort of things are made out of gold?

Some Groups of Elements Scientists classify things into groups. Scientists have grouped elements several different ways. One way divides elements into metals and nonmetals. About 75 percent of all elements are metals.

Some Groups of Elements Many metals, like iron, gold, and silver, are elements. However, not all metals are elements. Steel, for example, is made up of at least two elements, iron and carbon.

Do not conduct electricity very well Both can be elements Metals Nonmetals Shiny Malleable, (easy to shape or form) Ductile, (can be pulled into thin strands without breaking) Electricity flows through metal wires Dull Most nonmetals are brittle, if you try to stretch them, they will break Do not conduct electricity very well Both can be elements

Some Groups of Elements The noble gases are another group of elements. These six elements are neither metals nor nonmetals. They are unique because they are colorless and odorless. However, when electricity is added to some of them, like neon and argon, they glow.