What is matter?
anything that takes up space and has mass
Mass is the ___ of matter an object has.
quantity
atoms
basic units of matter
What are atoms composed of?
protons, neutrons, and electrons
central area of the atom
nucleus
What are located in the nucleus of an atom?
protons and neutrons
What move around the nucleus of an atom?
electrons
The number of ___ is equal to the number of ___.
electrons; protons
How many electrons can the first orbital hold?
2
How many electrons can the second orbital hold?
8
How many electrons is the third orbital stable with?
8
valence electrons
the electrons on the outermost shell
elements
substances made up of the same type of atom
Which 4 elements make up around 96% of the mass of all kinds of living things?
CHON (carbon, hydrogen, oxygen, nitrogen)
Atomic Number = ___
# of protons, # of electrons
Atomic Mass =
# of protons + # of neutrons
# of Neutrons =
atomic mass - atomic #
A
atomic number
B
chemical symbol
C
element name
D
atomic mass
Elements on the periodic table are organized in order of ___.
atomic number
periods of elements
rows that tell you the energy level
group/families of elements
columns that tell you the number of valence electrons
What do Lewis Dot diagrams represent?
valence electrons
isotopes
atoms of the same element that have a different number of neutrons
compounds
substances formed by bonding two or more elements in definite proportions
compound examples
water (H2O), carbon dioxide (CO2)
What does the chemical formula show?
the composition of the compound
octet rule
When the energy levels are not filled, atoms tend to react with other atoms to fill them.
chemical bonds
the force that holds together the atoms that make up compounds
Why do atoms form bonds?
to become more stable - they need a full outer shell of electrons
What are the two main types of strong chemical bonds?
ionic bonds and covalent bonds
ionic bonds
bonds in which electrons are transferred from one atom to another
ionic bond example
sodium chloride (table salt)
ions
charged atoms that have lost or gained electrons
Ions of opposite charge ___, forming ionic bonds.
attract strongly
covalent bonds
bonds in which electrons are shared between atoms
covalent bond example
methane
polar covalent bond
non-equal sharing of electrons
non-polar covalent bond
equal sharing of electrons
hydrophilic
water loving, ionic compounds, polar covalent
hydrophilic examples
salt, sugar, water
hydrophobic
water fearing, non-polar covalent
hydrophobic examples
oil, fats, waxes
molecules
two or more atoms bonded together
molecule examples
O2, H2