Physical Science Study Guide: Final Exam

Pure science is best defined as the

A. continuing search for new knowledge

A scientific theory is an explanation that

C. has been tested by many observations.

For a scientific theory to be valid, it must allow you to

d. make predictions

A scientific model is a

a. representation of a real event or object

Scientists use computer models to study complicated events and to

d. make predictions

A series of logical steps that is followed in order to solve a problem is called the

c. scientific method

The SI unit for measuring temperature is the

B. Kelvin.

The force with which gravity pulls on a quantity of matter is referred to as

d. weight

What is 78,900,000,000 expressed in scientific notation?

c. 7.89 * 10^10

The smallest unit of a substance that behaves like the substance is

c. a molecule

A molecule of water (H2O) is made from _____ combining two hydrogen atoms and one oxygen atom

d. chemically

You put 1 gram of salt into 1 liter of water and stir. The resulting liquid is an example of

C. a homogeneous mixture

A material that can be represented by a chemical formula is

d. pure substance

Which of the following is an example of a gas-liquid mixture?

B. a carbonated drink.

Knowing the chemical properties of a substance will tell you how the substance

d. reacts with other substances.

Which state of matter will hold its shape without a container?

a. solid

Which of the following is an example of a physical change?

a. dissolving salt in water

Temperature is a measure of the average ______ energy of the particles in the object.

b. kinetic

Which state of matter has a definite volume, but not shape?

c. liquid

What determines the speed of the atoms and molecules of a particular substance?

c. Both (a) and (b)

Pascal's principle states that a fluid in equilibrium enclosed by a vessel exerts pressure _________

c. equally in all directions

The kinetic theory states that the higher the temperature, the faster the

a. particles that make up a substance move.

The change of a substance from a solid directly to a gas is called

d. sublimation

The ability to change or to move matter is referred to as

b. energy

When a fixed sample of gas increases in volume, it must also

c. Either (a) or (b)

Pressure is calculated by dividing fore by the _____ over which the force is exerted

b. area

Buoyant force is the ____ force exerted on an object immersed or floating on a liquid

b. upward

Atoms have no electric charge because they

c. have an equal number of electrons and protons

As the temperature of a fixed amount of gas at constant volume decreases, its pressure

a. decreases

According to Bohr's model of the atom, electrons behave like

a. planets orbiting the sun.

Atoms of elements that are in the same group have the same number of

c. valence electrons

Ionization refers to the process of

d. losing or gaining electrons

Oxygen's atomic number is 8. This means that an oxygen atom has

c. eight protons in its nucleus

An atom's mass number equals the number of

b, protons plus the number of neutrons

Molar mass is defined as

d. the mass in grams of 1 mole of a substance

An ionic bond is a bond that forms between

a. ions with opposite charges.

Covalent bonds are formed between

C. nonmetal atoms

In order to determine speed, you must know

c. Both (a) and (b)

The difference between speed and velocity is that velocity includes

a. direction

Acceleration is defined as the change in velocity divided by

c. time.

When the velocity of an object changes, it is acted upon by a(n)

a. force.

A tug-of-war that results in one team pulling the other across the line is an example of

d. unbalanced forces.

Which of the following best illustrates balanced forces?

b. a stretched rubber band being held between two hands

Friction is defined as

a. a force that opposes motion between two surfaces that are touching

Which of the following is a displacement?

d. 3 blocks east.

Which is an example of balanced forces acting on an object?

d. a leaf lying on the grass.

Which of the following is a not a factor in calculating momentum?

c. acceleration.

What is the unbalanced force that slows down a ball rolling across the floor?

a. the force of friction.

When gravitational forces and air resistance equalize on an object that is falling toward Earth and the object stops accelerating, what is the velocity of an object called?

b. terminal velocity

What happens immediately after a skydiver opens her parachute?

a. Air resistance greatly increases.

What are the units of power?

d. All of the above.

A wheelbarrow is an example of a

b. second-class lever

An inclined plane

C. changes both the magnitude and the direction of the force

Gravitational potential energy depends on the

d. all of the above

Temperature is

d. All of the above

As the kinetic energy of the molecules in a substance increases, the

a. temperature of the substance increases.

The transfer of energy caused by the collision of molecules is called

b. conduction.

Energy from the sun reaches Earth by

b. radiation only.

Convection currents rise in air because

b. cool air descends and hot air rises

Which of the following statements is true?

b. Energy as heat flows from a higher temperature to a lower temperature.

In an air conditioner, a substance that easily evaporates and condenses is used to transfer energy from a room to the air outside. When the substance evaporates,

a. it absorbs energy as heat from the surrounding air.

(PHOTO NEEDED) Using the table, determine which substances can absorb the most energy in a temperature increase of 1 K

a. liquid water.

A combustion engine uses what kind of energy to do work?

b. heat

Sound waves are

b. longitudinal waves

The frequency of a sound wave determines the

a. the pitch of the sound.

How loud a sound is depends on

C. The amplitude of the waves

The difference between visible light and X rays is that

d. the frequency of X rays is greater.

The color of a light is determined by ______ of the light waves

c. the frequency

Which type of electromagnetic wave has the greatest wavelength

c. radio waves

The frequency of a sound wave is determined by the

A. source of the wave.

Resonance refers to an effect in which the

a. vibration of one object causes another object to vibrate at natural frequencies.

Which type of electromagnetic waves has the highest frequency?

a. gamma rays.

The law of reflection states that when light rays reflect off surface the angle of incidence

b. equals the angle of reflection.

An orange looks orange because it

a. reflects orange light and absorbs other colors

The color that an object appears to be depends on the

c. wavelengths of light that the object reflects.

When light moves from a material in which its speed is higher to a material in which its speed is lower, it is

a. bent toward the normal

White light breaks into different colors when it passes through a prism because of

a. differences in wave speed.

Which drawing illustrates the law of reflection? (PHOTO NEEDED)

c. C

There is a repulsive force between two charged objects when

c. their charges are of like sign.

When there is an equal amount of positive and negative charges on a n object, the object is

c. neutral

Electric field lines

d. All of the above

Batteries typically have

c. one positive and one negative terminal

Potential differences cause

b. electrons to move from the negative terminal to the positive terminal.

The SI unit of resistance is the

c. ohm

Whether or not charges will move in a material depends partly on how tightly ____ are held in the atoms of the material

a. electrons

Appliances connected so that they form a single pathway for charges to flow are connected in a(n)

a. series circuit

The north pole of one magnet will be attracted to

c. the middle of a magnet

Magnetic force

d. All of the above.

The magnetic field strength of a magnet

decreases as distance from the magnet increases

Magnetic fields exist

d. All of the above

A compass needle naturally points toward

d. All of the above

What causes a compass needle to point to geographic north?

b. The compass needle aligns with Earth's magnetic field.

Magnetic fields are produced by

b. electric currents

The strength of the magnetic field of a solenoid can be increased by

c. inserting an iron rod.

In a magnetized substance, the domains

b. line up more uniformly in one direction.

A device that converts electric energy into mechanical energy is a(n)

b. electric motor

A potential difference causes

b. Electrons to move from the negative terminal to the positive terminal of a battery.

An electric motor and a generator are similar in that both

c. transform energy into a different form.

Light travels as

c. electromagnetic waves.

A transformer changes

a. both the amperage and the voltage of an electric current.