module 1&2
tentative explanation for an observation
hypothesis
the number of protons in an atom
atomic mass
a chemical reaction that absorbs energy from its surroundings
endothermic reaction
physical measurement containing both magnitude and direction
vector quantity
a push or pull that acts on an object
force
any factor that changes in an experiment
variable
the sum of the protons and neutrons in the nucleus
mass number
a chemical reaction that releases energy
exothermic reaction
the time rate of change of an object's velocity
acceleration
friction that opposed the initiation of motion
static friction
metric measurement of mass
grams
electrons in the outermost (highest energy) level
valence electrons
chemical formula for carbon dioxide
CO2
the formula to calculate velocity
v= d/t
newton's first law of motion
an object at rest remains at rest... inertia
these are pure substances that contain more than one type of atom
compound
chemical bond between oppositely charged ions
ionic bond
this element is always present in a combustion reaction
oxygen
what this measurement shows: 4.5 ft/min2 north
acceleration
newton's 2nd law written as a formula
F=m x a
breaking a compound down into its elements
chemical change
the substances before a reaction, and after the reaction
reactants, products
6.02x1023 is the number of particles in one _______ of any substance
mole
when velocity does not change, acceleration is ________
zero
newton's 3rd law states:
for every action there is an equal and opposite reaction