8th Grade Physical Science Semester 2 Final Exam Study Guide

Multiple Choice
Identify the choice that best completes the statement or answers the question.

	1.	In an atom, the number of protons equals the number of
a.	nuclei.	
b.	electrons.	
c.	neutrons.	
d.	isotopes.	

	2.	Which particles in atoms have a negative electric charge?
a.	electrons	
b.	protons	
c.	neutrons	
d.	nuclei	

	3.	Fluorine, chlorine, bromine, and iodine are part of a family called
a.	noble gases.	
b.	metalloids.	
c.	halogens.	
d.	alkali metals.	

	4.	The tendency of an object to resist change in its motion is known as
a.	mass.	
b.	inertia.	
c.	force.	
d.	balance.	

	5.	The force of gravity on a person or object on the surface of a planet is called
a.	mass.	
b.	terminal velocity.	
c.	weight.	
d.	free fall.	

	6.	The force that one surface exerts on another when the two rub against each other is called
a.	friction.	
b.	acceleration.	
c.	inertia.	
d.	gravity.	

	7.	The law of universal gravitation states that any two objects in the universe, without exception,
a.	attract each other.	
b.	repel each other.	
c.	combine to provide a balanced force.	
d.	create friction.	

	8.	The product of an object’s mass and velocity is called its
a.	inertia.	
b.	momentum.	
c.	acceleration.	
d.	force.	

	9.	An object that travels around another object in space is called a(n)
a.	projectile.	
b.	inertia.	
c.	mass.	
d.	satellite.	

	10.	In physical science, a push or a pull is called a(n)
a.	force.	
b.	acceleration.	
c.	inertia.	
d.	motion.	

	11.	The amount of matter in an object is called its
a.	inertia.	
b.	mass.	
c.	force.	
d.	balance.	

	12.	The force that pulls falling objects toward Earth is called
a.	gravity.	
b.	free fall.	
c.	acceleration.	
d.	air resistance.	

	13.	The SI unit for force is the
a.	newton.	
b.	meter.	
c.	kilogram.	
d.	pound.	

	14.	When an object’s distance from another object is changing,
a.	it is in motion.	
b.	it is speeding.	
c.	it has a high velocity.	
d.	it is accelerating.	

	15.	The basic SI unit of length is the
a.	meter.	
b.	foot.	
c.	inch.	
d.	mile.	

	16.	Speed equals distance divided by
a.	time.	
b.	velocity.	
c.	size.	
d.	motion.	

	17.	Average speed is
a.	equivalent to velocity.	
b.	the rate at which an object is moving at a given instant.	
c.	the rate at which a slope changes.	
d.	the total distance traveled divided by the total time.	

	18.	A place or object used for comparison to determine if something is in motion is called
a.	a position.	
b.	a reference point.	
c.	a constant.	
d.	velocity.	

	19.	The International System of Units is used
a.	only in the United States.	
b.	only in France.	
c.	in most of Europe.	
d.	all over the world.	

	20.	If you know the distance an object has traveled in a certain amount of time, you can determine
a.	the size of the object.	
b.	the speed of the object.	
c.	the location of the object.	
d.	the acceleration of the object.	

	21.	If a bicyclist travels 30 kilometers in two hours, her average speed is
a.	30 km/h.	
b.	60 km/h.	
c.	15 km/h.	
d.	2 km/h.	

	22.	A classroom measures 4.33 meters wide. How wide is the classroom in centimeters?
a.	0.433 cm	
b.	43.3 cm	
c.	433 cm	
d.	4,330 cm	

	23.	Kilo- is a prefix that means
a.	one thousandth	
b.	one hundredth	
c.	one hundred	
d.	one thousand	

	24.	The range of electromagnetic waves placed in a certain order is called the
a.	electromagnetic spectrum.	
b.	electromagnetic wavelength.	
c.	electromagnetic frequency.	
d.	electromagnetic field.	

	25.	A packet of light energy is called a
a.	wavicle.	
b.	photon.	
c.	wave.	
d.	photoelectron.	

	26.	For work to be done on an object,
a.	some force need only be exerted on the object.	
b.	the object must move some distance as a result of a force.	
c.	the object must move, whether or not a force is exerted on it.	
d.	the object must not move.	

	27.	If you exert a force of 20 newtons to push a desk 10 meters, how much work do you do on the desk?
a.	200 joules	
b.	30 joules	
c.	10 joules	
d.	100 joules	

	28.	Work is measured in
a.	meters.	
b.	pounds.	
c.	joules.	
d.	newtons.	

	29.	A ramp is an example of a simple machine called a(n)
a.	inclined plane.	
b.	wedge.	
c.	lever.	
d.	pulley.	

	30.	A machine that utilizes two or more simple machines is called a
a.	combination machine.	
b.	compound machine.	
c.	mechanical machine.	
d.	mixed machine.	

	31.	Work equals force times
a.	energy.	
b.	velocity.	
c.	distance.	
d.	mass.	

	32.	Power is measured in units called
a.	joules.	
b.	pounds.	
c.	watts.	
d.	newtons.	

Completion
Complete each statement.

	33.	Each element is given a specific _________________________ that usually consists of one or two letters.

	34.	The ____________________ is the very small center core of an atom.

	35.	A(n) ____________________ is an object that is thrown.

	36.	Because the moon travels around Earth, it is a(n) ____________________.

	37.	If a car is speeding up, its initial speed is ____________________ than its final speed.

	38.	A jar lid is an example of a simple machine called a(n) ____________________.

	39.	A ramp in a parking garage is an example of a simple machine called a(n) ____________________.

Short Answer

	40.	What is the mass number of sodium?

	41.	What is the total number of electrons in an atom of sodium?

	42.	How many neutrons are in an atom of magnesium?

	43.	What is the atomic number of aluminum?

	44.	How many protons are in an atom of phosphorus?

	45.	If a metal reacts violently with water, in which group is it likely to be found?

	46.	What name is given to the elements in Groups 3 through 12? How do their properties tend to compare with the elements to the left and right of these groups?

Essay

	47.	Compare the properties of metals and nonmetals.

	48.	A book is sitting on the dashboard of a car that is stopped at a traffic light. As the car starts to move forward, the book slides backward off the dashboard. Use the term inertia to explain what happened.

	49.	Explain how to find the average speed of a car that travels 300 kilometers in 6 hours. Then find the average speed.

	50.	Explain why wedges and screws are actually types of inclined planes.