Chapter 2 Flashcards
(36 cards)
Matter
Anything that takes up space & has mass
Elements
is a substance that cannot be broken down to simpler substances by ordinary chemical means.
Atoms
is the smallest part of an element that displays the properties of the element.
Atomic symbol
One or two letters
Stands for element name
electron shells
indicate the average location of the electrons
AVG energy levels of electrons
Atomic number
PROTONS housed in nucleus
All atoms of element have
mass number
The sum of the protons and neutrons in the nucleus.
Isotopes
atoms of the same element that differ in the number of neutrons.
atomic mass
Atomic mass refers to the average mass for all the ISOTOPES of that atom.
valence shell
An ATOMS last ring
is important, because it determines many of an atom’s chemical properties
First Shell
Closest to nucleus
Two electrons
Second shell
Can contain 8 electrons
Period
Tells you how many shells an ATOM has.
octet rule
states that atoms react with one another in order to have a stable valence shell; the valence shell is most stable when it has eight electrons
In the process, they form (compounds) and/or (molecules)
molecule(chem)
exists when two or more of the same type of atoms bond together;
Compound
An MOLECULE containing atoms of at least two different elements
Protons
Positive charge; within atoms nucleus
Electrons
Negativity charged; on rings around nucleus
Neutron
No charge; within atoms nucleus
Formula
tells you the number of each kind of element in a
compound or molecule.
Ions
are formed when atoms lose or gain one or
more electrons to achieve a completed valence shell
Ionic bond
The interaction of oppositely charged ions
forms
Covalent Bond
occur when atoms share one or more pairs of electrons.
There are single, double, and triple
non-polar covalent bonds
the atoms share the electrons equally.
