Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.

By signing up, I agree to StudyStack's Terms of Service and Privacy Policy.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.

Remove ads
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards

Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how


Democritus a Greek philosopher, believed that the universe was made of empty space and tiny bits of stuff. He called these tiny bits of stuff “atoms.” He believed that different types of atoms existed for every type of matter.
Antoine Lavoisier a French chemist, conducted a series of experiments involving chemical reactions, proving that matter could not be created or destroyed, it only changed form; law of conservation of matter.
John Dalton an English chemist, introduced an early atomic theory of matter.
J.J. Thomson an English physicist, discovered negatively charged electrons using a cathode ray tube.
Ernest Rutherford a New Zealand-born English physicist, conducted his gold foil experiment; discovered the positively-charged center of the atom—the nucleus, as well as discovered positively charged protons; determined that atoms were mostly empty space.
James Chadwick a student of Rutherford’s, discovered neutral (meaning “no charge”) neutrons in the nucleus of an atom. His proton-neutron model of the atomic nucleus is still accepted today.
Niels Bohr a Danish physicist, proposed that electrons were located in specific energy levels and that electrons traveled in definite orbits around the nucleus. His atomic model is often called the “planetary model.”
Dmitri Mendeleev a Russian chemist, created the first periodic table that was arranged by increasing atomic mass.
Created by: S730503