introduction to chemistry powerpoint

Introduction to Chemistry

Matter and Atoms and Elements…Oh My!

What’s the MATTER with you?

• Some of us have Grey Matter

• Sometimes it seems Mr. Capizzi has something the matter with him!

• But that’s not what we’re talking about…

What is MATTER???????

• Matter is anything that has Mass and takes up space

• What is the scientific term for how much space something takes up?

Volume

And now an incredibly short, brief, concise, curtailed, condensed, terse, succinct, direct, laconic, sententious… (breathe)

…history of the atom

Those Pesky Ancient Greeks!

• 2,500 years ago some Greek philosophers believed that matter was composed of tiny particles

• They thought that if you cut something in half… then cut it in half again…

• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…• then cut it in half again…

• Eventually, you would have a piece soooooooooo tiny that you couldn’t cut it anymore…

• They named this tiny piece the Atom, which means “indivisible” in Greek

• This idea was so popular that it didn’t change for over 2,000 years!

It’s Elementary My Dear Watson!

• In the 1800’s scientists began to investigate the properties of matter

• They found that some substances could be combined with others to make new substances

• While other substances could be taken apart to find out what they were made from

It’s Elementary My Dear Watson!

• Some substances couldn’t be broken down into simpler substances

• They called these substances elements

• An Element is matter that is made of only one kind of atom.

For example: Iron is made only of iron atoms, gold is made of only gold atoms, etc.

Imagining the Atom

• Atoms are so small that some scientist have estimated that 5 trillion of them could fit on the tip of a needle!

• So how do scientists study something so small they can’t see?

America’s Next Top Model

• Many scientists developed models of the atom

• It’s not important that you remember them all!

• It’s important that you know that there have been many models of the atom

• As new theories are thought up, new models must be created…That’s Science!

America’s Next Top Model

• Using a Cathode Ray Tube and a battery, scientists discovered that atoms contain negatively charged particles called electrons

• Cathode Ray Tube video

America’s Next Top Model

• Another scientist named Rutherford (he has an element named after him) ran an experiment and found that atoms also contain a positively charged particle called a proton

America’s Next Top Model

• Other scientists used Rutherford’s results to discover yet another particle inside the atom

• The Neutron

• A neutron has a neutral (or no) charge and almost the same mass as a proton

America’s Next Top Model

America’s Next Top Model

• Although scientists feel confident that protons and neutrons are found inside the nucleus –the center of an atom,

• they still debate the location of the electrons

America’s Next Top Model

• We will soon talk about electrons appearing in levels around the nucleus

• Electrons spend most of their time in these levels, however

• Scientists believe electrons are constantly moving in a “cloud” around the nucleus

Questions for Review…

• What is matter?• What is an element? Provide an example of an

element.• What are the three particles of an atom and what

are their charges?• What is the nucleus of an atom and what does it

contain?• Why are models important for studying

atoms?

Thank You for your attention… Any Questions?