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.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

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.
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

Definitions Ch 8

Exam 4

Atomic mass unit amu Small unit used to describe the mass of an atom.
Average atomic mass It means that any sample of C can be treated as it were made up of identical carbon atoms.
Mole Unit use to measure the amount of a chemical substance. It helps to convert from particles to mass of a substance. The number of atoms present in 12.01 g of C
Avogandro's number One mole of something is 6.022 x 10^23 units of that substance.(Symbol N) Ex. A mole of water is 6.022 x 10^23 H2O molecules.
Molar mass/ Molecular weigh T: Sum of the atomic masses of each element in a formula B: The mass of 1 mol of the substance (g) (MM)... Remember diatomic elements and count 2 times.
Formula weight Sometimes used to name the molar mass for ionic compounds like NaCl.
Percent composition Gives the mass % of each element in a substance. Formula: Divide the total mass of an element by the total mass of the molecule and then multiply by 100.
Empirical Formula (Simplest formula) The smallest whole-number ratio of elements in a formula. Can be the same for various compounds.
Molecular Formula T: multiple of the empirical formula. B: Gives the composition of the molecules that are present in a compound(Without simplifying).
Created by: lesliemelissa19