Atomic Theory

Big Idea 8: Properties of Matter

Atoms and States of Matter

Big Idea 8: Properties of Matter

• All objects and substances in the world are made of matter. Matter has two fundamental properties: matter takes up space and matter has mass which gives it inertia.

• Objects and substances can be classified by their physical and chemical properties. Mass is the amount of matter (or "stuff") in an object. Weight, on the other hand, is the measure of force of attraction (gravitational force) between an object and Earth.

• The concepts of mass and weight are complicated and potentially confusing to elementary students. Hence, the more familiar term of "weight" is recommended for use to stand for both mass and weight in grades K-5. By grades 6-8, students are expected to understand the distinction between mass and weight, and use them appropriately.

Explore the scientific theory of atoms (also known as atomic theory) by recognizing that atoms are the smallest unit of an element and are composed of sub-atomic particles (electrons surrounding a nucleus containing protons and neutrons). (SC.8.P.8.7 - DoK 1)

• A scientific theory is supported by evidence and is different from an opinion, belief, or hypothesis. Because theories are based on evidence, they may be modified as better technology is developed and new evidence is collected, but they are rarely discarded completely.

• Scientific theories are different from laws because they explain why something occurs in the the natural world, rather than what is occurring. Because of this scientific theories never become laws and laws never become theories.

• Every THING in our universe contains matter and is made of atoms and molecules. The only things that are not are not actual things, like energy and forces.

• Atoms are made of sub-atomic particles. Protons and neutrons make up the nucleus, or center of the atom, while electrons orbit the nucleus.

• Protons have a postive charge, while electrons have a negative charge and neutrons are neutral, or have no charge.

• Protons and neutrons each have one atomic mass unit, while electrons are so small that their mass is considered insignificant.

• Elements are all of the different types of atoms and are identified by their number of protons.

Multiple Choice

Neon (Ne) is an element, one of many different kinds of matter that occur on Earth. The diagram shows a model of one atom of the element neon. Which of the following statements best describes the atom shown in the diagram?

• It is identical with atoms of some other elements.

• It can be broken down into smaller parts by chemical means.

• It is the smallest unit of neon that has all the properties of neon.

• It is the largest unit of neon that can combine with other elements.

Multiple Choice

Neon (Ne) is an element, one of many different kinds of matter that occur on Earth. The diagram shows a model of one atom of the element neon. The atom of neon shown is made up of subatomic particles. Which of the following are shown in the diagram?

• electrons

• neutrons

• protons

• ions

Multiple Choice

In its natural state, neon has no definite shape or volume. Its atoms move fast and are far apart. Which term describes neon in its natural state?

• gas

• liquid

• solid

• solution

Multiple Choice

Which is the smallest unit of matter?

• compound

• mixture

• atom

• nucleus

Multiple Choice

The illustration is a model of an atom. Which two subatomic particles make up the nucleus of an atom?

• proton and electron

• neutron and proton

• electron and neutron

• ion and proton

Multiple Choice

Contributes basically no mass to an atom.

• protons

• neutrons

• electrons

• protons and neutrons

Multiple Choice

True or False: The majority of an atom is made up of empty space

• True

• False

Multiple Choice

People have always agreed that matter is made of atoms.

• True

• False

Multiple Choice

All matter is made of

• energy

• atoms

• air

• chemistry

Multiple Choice

Something that takes up space and has mass.

• volume

• matter

• mass

• density

Multiple Choice

Why is the overall charge of an atom neutral (0)?

• They have the same number of protons and neutrons.

• They have the same number of protons and electrons.

• They have the same number of electrons and neutrons.

Multiple Choice

What particle uniquely identifies an element?

• Number of Valence Electrons

• Number of Protons

• Number of Electrons

• Atomic Mass

Multiple Choice

What subatomic particles would you find in the nucleus of an atom?

• Protons only

• Protons and Neutrons

• Neutrons and Electrons

• Protons and Electrons

Multiple Choice

What two particles determine the mass number?

• Protons and electrons

• Electrons and neutrons

• Protons and neutrons

Multiple Choice

The positive particles of an atom are

• electrons

• positrons

• neutrons

• protons

Multiple Choice

How did each model of the atom help to develop the atomic theory?

• Each model provided opinions that were added.

• Each model showed different properties of the same structure.

• Each model showed new particles that had been discovered.

• Each model built upon the other to show new particles or properties of previously discovered particles.

Explore the scientific theory of atoms (also known as atomic theory) by using models to explain the motion of particles in solids, liquids, and gases. (SC.8.P.8.1 - DoK 2)

• The kinetic energy, or motion, of the particles (atoms and molecules) in a substance determine its state of matter. Atoms are ALWAYS moving. The four states of matter are: solid, liquid, gas, and plasma.

• Solids have particles that are packed closely together and vibrate in place. Anything in the form of a solid is technically "frozen".

• When you add energy (heat) to a solid, it will eventually reach its melting point and change states to a liquid. Freezing point and melting point are technically the same thing, it just depends on whether energy is being added or taken away from the substance.

• The particles in a liquid have enough energy that they are able to slide past/around each other. Liquids take the shape of the container they are held in.

• When you add energy (heat) to a liquid, it will eventually reach its boiling point and change states to a gas. During a state change, temperature remains constant.

• The particles in a gas are moving rapidly and fill the shape and space of their container.

• Plasma has all of the same properties of a gas, except its particles have an electrical charge. The sun, lighting, and fluorescent light bulbs are all plasma.

Multiple Choice

Madison is heating two different liquids. For each liquid, she wants to compare the temperatures at which gas bubbles form, rise, and begin to escape. What physical property is Madison using to compare the liquids?

• boiling point

• conductivity

• melting point

• melting point

Multiple Choice

Melinda drew an illustration of the three states of matter. The illustration shows what she drew. Melinda wanted to replace the numbers with labels identifying the correct state of matter. How should she change the numbers?

• 1 --> solid; 2 --> liquid; 3 --> gas

• 1 --> gas; 2 --> liquid; 3 --> solid

• 1 --> liquid; 2 --> solid; 3 --> gas

• 1 --> liquid; 2 --> gas; 3 --> solid

Multiple Choice

Atoms and molecules are constantly in motion. The more energy the atom or molecule contains, the faster they move about. In which state of matter do the atoms and molecules have the most energy?

• in a gas

• in a solid

• in a liquid

• in both a liquid and a solid

Multiple Choice

As temperature increases, what happens to particles?

• They speed up

• They slow down

Multiple Choice

If the tops were removed from the cylinders, the following would happen:

• The solid would fly out of the container

• The liquid would fly out of the container.

• The gas would fly out of the container.

• They ALL would fly out of the container.

Multiple Choice

In the above diagram, "State of Matter B" is a liquid. This means that it has:

• definite shape and volume.

• no definite shape or volume.

• definite volume, but changing shape.

• definite shape, but changing volume.

Multiple Choice

Which state of matter does the diagram best represent?

• Solid

• Liquid

• Gas

Multiple Choice

What state of matter does the picture best describe?

• Solid

• Liquid

• Gas

Multiple Choice

What state of matter is segment 5?

• Solid

• Liquid

• Gas

• Plasma

Multiple Choice

Fluid states are

• solid and gas

• liquid and gas

• solid and liquid

• solid, liquid and gas

Multiple Choice

From 30 degrees to 55 degrees, what state of matter is the substance?

• Solid

• Liquid

• Gas

• Plasma

Multiple Choice

Which is a property of matter that you CANNOT observe just by looking at an object?

• temperature

• shape

• color

Multiple Choice

At higher temperatures

• particles in an object have less energy

• particles in an object move faster

• a gas contracts

Multiple Choice

Define a liquid.

• Indefinite shape, indefinite volume

• Definite shape, definite volume

• Found in stars

• Definite volume, indefinite shape

Multiple Choice

The state of matter that has no definite size or shape is

• Solid

• Liquid

• Gas

Multiple Choice

Particles (molecules) in a ______________________ have more energy than the other states of matter.

• gas

• solid

• liquid

Multiple Choice

Particles of a liquid

• are tightly packed together and stay in a fixed position.

• have no viscosity.

• decrease in volume with increasing temperature.

• are free to move around one another but still touch.

Multiple Choice

What term describes a liquid changing to a solid?

• Deposition

• Sublimation

• Evaporation

• Freezing

Multiple Choice

How is a gas defined?

• Indefinite shape, indefinite volume

• Definite shape, definite volume

• Found in stars

• Definite volume, indefinite shape

Multiple Choice

Which form of matter does not take the shape of its container?

• liquid
• gas
• solid
• air

Multiple Choice

True or False: During a state change, temperature does not change.

• True

• False