Atom!

An Atom is the smallest particle into which an element can be divided and still be the same substance. :]

Setting: In 440 BC Democritus thought that you would eventually end up with a particle that could not be cut. he called it an Atom. Aristotle disagreed with him. he thought you would NEVER end up with a particle that could not be cut.

In 1803 a man named John Dalton published a theory about atoms. it said: 

*All substances are made of atoms. Atoms are small particles that cannot be created, divided, or destroyed.

*Atoms of the same element are exactly alike. Atoms of different elements are different.

*Atoms join with other atoms to make new substances.

    [Top Photo:Democritus, Bottom Photo: John Dalton]

                              ****

Atoms contain electron clouds that cirlce a dense nucleus.

Atoms are very small, but they are made of even smaller particles. these particles are protons, neutrons, and electrons.

the most massive particles in an atom are the protons and nuetrons.

The number of protons in the nucleus of the atom is the Atomic number.

WELL HOW small ARE ATOMS? 

a penny contains about about: 20,000,000,000,000,000,000,000 atoms! [twenty thousand billion atoms!] think about it, a penny is pretty small. if that many atoms can fit inside of it,imagine how big atoms are!  

                                  Trivia Time!

                  [answer these questions using what you know about atoms.]

1. How many protons are in Calcium if its atomic number is 20?

       a) 2

       b)  7

       c)  20

       d) 10

2. True or False? Electrons and Nuetrons are the most massive paricles in an atom.

3. atoms of the same element are exactly alike. atoms of different elements are ________.

4. Who published the atomic theory and in what year?

                [check your answers in the bottom of the "so what"  section.]

                  Here are some pictures of Atoms!

We study Atoms because they are the center of almost all science. Everything is made of atoms. therefore if you know about atoms, you can have a better understanding of the particle or element you are studying.

Trivia Time Answers

1. C

2. False, protons and nuetrons are the most massive particles in an atom.

3. Different

4. John Dalton, 1803

key:

1 correct= You probably sleep in class.

2 correct= Amatuer scientist wanna-be.

3 correct= Scientist.

4 correct= Genius.

If you have questions or comments for my page, just write them in "comments".

Wikipedia Contributors, "Atoms." Wikipedia. 2008. Wikipedia, The Free Encyclopedia. 8 Apr 2008 <http://en.wikipedia.org/wiki/Atoms>.