How can we help?

You can also find more resources in our Help Center.

12 terms

Chapter 2 Section 1

STUDY
PLAY
atom
smallest particle of matter that contains the characteristics of an element
nucleus
central region of an atom
protons
same mass as neutron, located in nucleus
neutrons
same mass as protons, located in the nucleus
electrons
smallest of three particles in an atom, located on energy levels
valence
outermost energy level
molecule
combined atoms
compound
contains 2 or more elements chemically combined in specific proportions
atomic number
number of protons in the nucleus
mass number
total mass, protons+neutrons
isotope
atoms with the same number of protons but different number of neutrons
ion
has an electrical charge because of a gain or loss of one or more electrons