Like this study set? Create a free account to save it.

Sign up for an account

Already have a Quizlet account? .

Create an account

Chapter 4


Is the smallest particle of an element that retains its identity in a chemical reaction.

atomic mass

the weight average of the masses of the isotopes of an element

atomic mass unit

a unit of mass equal to one-twelfth the mass of a carbon-12 atom

atomic number

the number of protons in the nucleus of an atom of an element

cathode ray

a stream of electrons produced at the negative electrode of a tube containing a gas at low pressure.

Dalton's atomic theory

the first theory to relate chemical changes to events at the atomic level.


a negatively charged subatomic particle


a vertical column of elements in the periodic table; the constituent elements of a group have similar chemical and physical properties


atoms of the same element that have the same atomic number but different atomic masses due to a different number of neutrons.

mass number

the total number of protons and neutrons in the nucleus of an atom


a subatomic particle with no charge and a mass of 1 amu; found in the nucleus of an atom


the tiny, dense central portion of an atom, composed of protons and neutrons.


a horizontal row of elements in the periodic table

periodic table

an arrangement of elements in which the elements are separated into groups bases on a set of repeating properties


a positively charged subatomic particle found in the nucleus of an atom

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

Voice Recording