EVERYTHING

is made of

ATOMS

Ms Vogt’s Version

Atoms are the basic units of all matter.

• Proton - A positively charged particle in the nucleus of an atom.

• Neutron - A neutral particle in the nucleus of an atom.

• Electron - negatively charged particle orbiting the nucleus.

• Nucleus - center of the atom, composed of protons and neutrons.

• Orbital - Energy levels in the cloud of electrons surrounding the nucleus.

Atoms make up all of the 118 known ELEMENTS

• Elements are pure substances that cannot be broken down into any other substance by chemical or physical means.

• Elements are identified by the number of protons in their nucleus. This is called their ATOMIC NUMBER

Atoms are often drawn like this:

Electron Proton Neutron Orbital

This is an atom of the element Beryllium.

It has 4 protons, 4 electrons, and 4 neutrons

But remember:• This is only a model. Atoms do not really

look like this. This just helps us to visualize the particles that make up an atom.

• In reality, atoms are mostly empty space. There is a big distance between the nucleus and the electrons.

• Electrons never stop moving. They whiz around the nucleus around 22oo km per second. The orbitals (energy levels) show us the “altitude” they are in.

The Periodic Table of Elements

• This is a chart that organizes everything in the universe - everything! How exciting is that?

• Each element has a square on the periodic table that gives us important information about it.

• A very smart man named Mendeleev invented it. My hero!

He’s awesome.

He organized the universe!! He could not see atoms. All this by 1869. Dude is smart.

Info on the PT1. Name of the Element

2. 1 or 2 Letter symbol. First letter is capitalized the second is not.

3. Atomic Number - number of protons.4. Atomic Mass - an average of the number of

protons and neutrons in the nucleus. Neutrons can be different without changing the element.

Nitrogen

7

14.007

Atomic Number: the number of protonsNitrogen has 7 protons and 7 electrons

Symbol

Name

Atomic Mass: Protons + NeutronsNitrogen has 7 neutrons on average.

Rules for Drawing an Atom

1. Atomic Number = the number of protons.

2. The number of electrons = the number of protons. (not always but we will get into that later)

3. The number of neutrons = the Atomic mass - the atomic number. Just round the mass to the nearest whole number.

and then it gets complicated…

• Electrons get put in orbitals around the nucleus.• We will concentrate on elements that use only three orbitals.

#1-20 on the PT. After that it gets insane -something to look forward to in high school!

• 1st orbital holds 2 electrons• 2nd orbital holds 8 electrons• 3rd orbital holds 8 electrons• You start filling from the inside orbital and the fill outwards.

Each orbital must be full before you move to the next one.

What does this look like?

Nitrogen

7

14.007

Now you try!

5

BBoron

10.811

How many protons does Boron have?

How many neutrons does Boron have?

How many electrons does Boron have?

How many orbitals will Boron have?

5 protons, 5 electrons, 6 neutrons (11-5), 2 orbitals

Use your PT to draw 2 elements (#1-15) in your journal!!

Tape the sheet into your notebook and choose any 2 to draw.