Elements

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Slide 1

Elements

Examples of certain chemical elements. From left to right: hydrogen, barium, copper, uranium, bromine, and helium.

Slide 2

What is an element?

A element is a pure substance made of one type of atom

Elements are divided into metals and non-metals

Examples of non-metal elements include carbon, oxygen, hydrogen, and nitrogen

Examples of metal elements include aluminum, iron, copper, and gold

A gold bar

Slide 3

Atoms

All the matter we can see is made of very small particles called ‘atoms.’

They are not the smallest things we know of, but they are so small we can’t see them except with the most powerful microscopes. (A microscope is a tool for looking at very small things.)

There are about 5.07 x 1024 or 5,070,000,000,000,000,000,000,000 atoms in a milliliter of water.

Slide 4

All atoms are made up of just 3 basic particles:

“Charge” causes objects to experience a force when near other electrically charged objects. It’s like a magnet.

Slide 5

Inside an atom

An atom has a nucleus in the middle, and electrons around the nucleus

The nucleus is made of protons and neutrons

An atom has the same number of protons as electrons so the + and - charges cancel to equal 0 charge for the atom

A helium atom

Question: Is the nucleus’ charge positive or negative?

Slide 6

Where did the elements come from?

The elements on our planet were mostly made before the Earth was made

The simplest elements, hydrogen and helium, were created when the universe was created

The other elements were made inside stars which later exploded

Most of your body’s atoms were made inside stars billions of years ago

Slide 7

What can elements do?

Some elements we need to stay alive, like oxygen. Oxygen is in air, and we would die in minutes without it

Other elements are very poisonous and even a small amount would kill us, like arsenic

Slide 8

Molecules

A molecule is a group of atoms that have joined together into one piece.

Molecules have 2 or more atoms in them, and some molecules have thousands or more atoms in them.

Here are some common molecules:

Water: H2O

Nitrogen: N2

Carbon Dioxide: CO2