7th Grade Physical Science Final Review

What tool is used to measure the mass of an object?

digital balance

What tool is used to measure temperature?

Thermometer

What is the basic metric unit of length?

Meter

Mass is defined as:

the amount of space an object takes up

What should you do if there is an accident or injury in the lab?

Raise your hand and tell the teacher

What are the building blocks of all matter?

Atoms

The length of a highway would most likely be measured in what metric units?

Kilometers

Write the chemical symbol for: oxygen:

O

Write the chemical formula for carbon dioxide:

CO2

Which one (oxygen or carbon dioxide) is an element?

Oxygen

How do you know?

Represented by a single capital letter

The density of water is

1 G/ml

An object with a density of 0.9g/mL will _____ in water.

float

How do you know if an object will float in water?

If it has a density of less than 1.0 g/ml

Round the following numbers to the nearest tenth (0.1).

444.444, 33.33, 55.55, 79.0

444.444- 444.4     33.33- 33.3    55.55- 55.6    79.0- 79

Which phase of matter is characterized by definite shape and a definite volume?

Solid

Which phase of matter is characterized by having neither definite shape nor definite volume?

Gas

In which phase of matter would water molecules have the most energy?

Gas

What is the electrical charge of a proton?

Positive

What is the electrical charge of a neutron?

neutral / no charge

What is the electrical charge of an electron?

Negative

What does the atomic number tell you?

The total number of protons

The small positively charged center of an atom is called the

Nucleus

In a neutral atom, the number of protons must equal

the number of electrons

List the Noble Gases:

Are the noble gasses reactive?

Helium, Neon, Argon, Krypton, xenon, and radon

No they have a full number of valence electrons

What part of an atom is involved during chemical bonding?

Electrons

On the periodic table, where are the metals found?

On the left side

In a chemical equation, the arrow represents the word

Yield

A form of shorthand using symbols and formulas to represent a chemical reaction is called a

Chemical Equation

A strong base could have a pH of

8-14

A strong acid could have a pH of

0-6

A neutral substance has a pH of

7

A substance that changes color in the presence of an acid or a base is called a/an

indicator

What is the mass of a proton?

1 amu

 What is the mass of a neutron?

1 amu

What is the mass of an electron?

0.0006 amu

Where are protons found in the atom?

In the nucleus

Where are neutrons found in the atom?

In the nucleus

Where are electrons found in the atom?

Outside the nucleus along orbitals  in the electron cloud

What do we call the very small center core of an atom?

Nucleus

Where are the most reactive metals found?

Group 1 and Group 2

List 3 properties of metals:

Conductors, malleable and luster ( metallic)

Three ways in which the solution rate can be increased are

crush it , heat it, and stir it.

What is an amorphous solid?

A solid object with no definite shape

Examples of chemical reactions include

digestion, and combustion

A change from a solid to a liquid is called

melting

A change from a liquid to a solid is called

freezing

Air, saltwater, and raisin bran are all example of

Homogenous mixture

List 3 properties of acids

Sour in taste, turns litmus paper red, Contains Hydrogen (h+) ions

List three properties of bases

bitter in taste, turns litmus paper blue, contains hydroxide Ions (OH)

What is the freezing point of water?

0⁰C

What is the boiling point of water?

100⁰C

What do the following prefixes mean:

kilo, centi, milli

kilo- 1000   centi- 1/100   milli- 1/1000

Matter is anything that

has a mass and takes up space

An educated guess is called a

hypothesis

In a controlled experiment, the factor being tested or changed is the

Independent variable

The universal solvent is

water

Of the following, which has the most amount of mass?

Neutron and Proton

On the periodic table, where are the most reactive metals?

Group 1 and group 2

On the periodic table, where are the most reactive nonmetals?

Group 17

On the periodic table, where are the least reactive elements?

Group 18

Signs of a chemical change include

color change, bubbling or fizzing  and a change in temperature

What is the density of a 40 gram object with a volume of 10mL?

4.0 g/ml

If an atom has an atomic number of 3 and a mass of 7, how many neutrons does this atom have?

How many protons?

4 neutrons and 3 protons

Why does a heated gas rise?

Hot air/ gas is less dense than cold air/gas

Why does oil float on top of water?

They have different densities

What is the basic unit of electric charge?

Coulomb

Name two types of electric charge

Positive or negative

What happens when you rub a balloon on your hair?

You create static electricity

What is an electric current?

A loop in which electrons are able to move producing electricity.

What are the three main components of a simple electric circuit?

Power source, load and conductive pathway (wire)

What's the difference between a conductor and an insulator? Give an example of each.

Conductors allow the flow of electricity through it where insulators do not. An example of a conductor  is copper, aluminum. An example of an insulator is rubber, plastic and glass.

What are the two poles of a magnet called?

North and south poles

Do like poles attract or repel each other?

Repel

What is the name of the area around a magnet where its force can be detected?

Magnetic field

Name three materials that are attracted to magnets.

Iron, Cobalt and Nickel

How can you make an electromagnet?

Wrap an insulated wire around a magnetic object

What type of wave is a sound wave?

Longitudinal

What does the frequency of a sound wave determine?

The number of cycles per second of wave in a given period of time

What does the amplitude of a sound wave determine?

The amount of energy the wave possesses

Through which medium does sound travel fastest: air, water, or solid?

Solid

What happens to sound waves when they hit a hard surface?

They bounce off

How are sound waves produced by musical instruments?

Through vibrations in the molecules

What type of wave is a light wave?

Transverse wave

What is the speed of light in a vacuum?

3 x 10^8