Praxis 5005 Physical Science
Matter - answer takes up space and has mass
Mass - answer a measure of the amount of matter in an object
Weight - answer the measure of the Earth's pull of gravity on an object
Volume - answer the amount of cubic space that an object occupies
Density - answer the mass of a substance contained per unit of volume
Specific gravity - answer the ratio of the density of a substance to the density of water
Physical properties of matter - answercan be observed or measured without changed
the composition of the substance (can be undone)
ex: odor, speed of evaporation, color, melting/freezing, mass, taste
Chemical properties of matter - answersubstance usually changes into another kind of
substance ( cannot be undone)
ex: lemon juice turning brown when heated
Law of conservation of matter - answermatter or mass cannot be created or destroyed,
it can change from one form to the next; the amount of mass will be the same before
and after
Compound - answertwo or more elements that have been chemically combined
ex: NaCl (salt)
Mixture - answerany combo of two or more substances in which the substances keep
their own properties
-homologous mixture is a solution
Elements - answera basic structure that cannot be simplified (hydrogen, gold, oxygen,
etc); made entirely from one type of atom
Atom - answerthe smallest amount of an element; made up of protons (+ electrical
charged), neutrons (carry no electrical charge) and electrons (- electrical charge)
, Molecule - answerthe smallest particle of a substance that can exist independently and
still have all of the properties of that substance
-composed of atoms
Motion - answerobjects is in motion when it is continuously changing its position relative
to a reference point
Speed - answerrate at which distance is covered during motion/rate of change of its
position (distance / time)
ex: mph, m/s
Distance - answerlength of path it takes (speed X time)
Time - answerduration over which movement or motion occurs (distance/ speed)
Acceleration - answermeasurement in change in an objects velocity; an object can
decrease speed, increase speed, or change direction
Formula: vf-vi
change in velocity/change in time
Circular motion - answermovement of an object along the circumference of a circle or
rotation along a circular path or a circular orbit; speed does not change but direction is
changing constantly (velocity); when the velocity changes, the object is undergoing
accelerated motion and acceleration is always directed toward the center
Relative motion - answerthe calculation of the motion of an object with regard to some
other object; reference point is important b/c we do all calculations according to
reference point
Newton's first law of motion - answerLaw of inertia: an object at rest will remain at rest
and an object in motion will remain in motion at a constant velocity unless acted upon
by an external force
Newton's second law of motion - answerif a net force acts on an object, it will cause the
acceleration of the object
F = ma
force = mass x acceleration
Newton's third law of motion - answerfor every action there is an equal and opposite
reaction
Matter - answer takes up space and has mass
Mass - answer a measure of the amount of matter in an object
Weight - answer the measure of the Earth's pull of gravity on an object
Volume - answer the amount of cubic space that an object occupies
Density - answer the mass of a substance contained per unit of volume
Specific gravity - answer the ratio of the density of a substance to the density of water
Physical properties of matter - answercan be observed or measured without changed
the composition of the substance (can be undone)
ex: odor, speed of evaporation, color, melting/freezing, mass, taste
Chemical properties of matter - answersubstance usually changes into another kind of
substance ( cannot be undone)
ex: lemon juice turning brown when heated
Law of conservation of matter - answermatter or mass cannot be created or destroyed,
it can change from one form to the next; the amount of mass will be the same before
and after
Compound - answertwo or more elements that have been chemically combined
ex: NaCl (salt)
Mixture - answerany combo of two or more substances in which the substances keep
their own properties
-homologous mixture is a solution
Elements - answera basic structure that cannot be simplified (hydrogen, gold, oxygen,
etc); made entirely from one type of atom
Atom - answerthe smallest amount of an element; made up of protons (+ electrical
charged), neutrons (carry no electrical charge) and electrons (- electrical charge)
, Molecule - answerthe smallest particle of a substance that can exist independently and
still have all of the properties of that substance
-composed of atoms
Motion - answerobjects is in motion when it is continuously changing its position relative
to a reference point
Speed - answerrate at which distance is covered during motion/rate of change of its
position (distance / time)
ex: mph, m/s
Distance - answerlength of path it takes (speed X time)
Time - answerduration over which movement or motion occurs (distance/ speed)
Acceleration - answermeasurement in change in an objects velocity; an object can
decrease speed, increase speed, or change direction
Formula: vf-vi
change in velocity/change in time
Circular motion - answermovement of an object along the circumference of a circle or
rotation along a circular path or a circular orbit; speed does not change but direction is
changing constantly (velocity); when the velocity changes, the object is undergoing
accelerated motion and acceleration is always directed toward the center
Relative motion - answerthe calculation of the motion of an object with regard to some
other object; reference point is important b/c we do all calculations according to
reference point
Newton's first law of motion - answerLaw of inertia: an object at rest will remain at rest
and an object in motion will remain in motion at a constant velocity unless acted upon
by an external force
Newton's second law of motion - answerif a net force acts on an object, it will cause the
acceleration of the object
F = ma
force = mass x acceleration
Newton's third law of motion - answerfor every action there is an equal and opposite
reaction
