GRADE: Seventh

CONTENT STANDARD: Physical Science

CONTENT TOPIC: Matter

CONCEPT: Matter and energy in the universe are governed by physical laws.

CONTENT OBJECTIVE: 7A1.00 To understand the structure of matter

INSTRUCTIONAL OBJECTIVES: The learner will:

1.01 define matter
1.02 list several examples of matter.
1.03 list the four phases of matter.
1.04 define each phase of matter.
1.05 give examples of each phase.
1.06 list the three subatomic particles.
1.07 define each subatomic particle.
1.08 explain the location of each subatomic particle.

I. Matter
A. Definition
B. Examples
II. Phases of matter
A. Solid
1. Definition
2. Examples
B. Liquid
1. Definition
2. Examples
C. Gas
1. Definition
2. Examples
D. Plasma
1. Definition
2. Examples
III. Atom
A. Definition
B. Subatomic Particles
1. Proton
2. Electron
3. Neutron
C. Location of Subatomic Particles
1. Nucleus
2. Electron Cloud

TN COMPONENT OF SCIENCE: Process of Science

TN GOAL:

To enable students to demonstrate the processes of science by posing questions and investigating phenomena through language, methods and instruments of science.

1.6 COMMUNICATING - An essential aspect of science is the act of accurately and effectively conveying oral, written, graphic or electronic information from the preparer to the user.

1.6a The sharing and disseminating of results should be done in a clear and concise manner.

BENCHMARK: Human beings learn complicated concepts from others through various methods of communication.

TIME REQUIRED:

45 minutes

Measuring cup or graduated cylinder, glass containers of various sizes and shapes, food coloring.

Matter, phase, volume

Today we will learn about the structure of matter and its phases.



This classroom connector addresses instructional objectives 1.01, 1.02, 1.03, 1.04, and 1.05

Matter is anything which has mass and occupies space. All around us are numerous examples of matter that we see, feel, smell or taste such as rocks, rabbit fur, smoke, or a chocolate chip cookie. These are just a few of the millions of examples of matter. Can you name some other examples of matter? (List examples given by students on the board.)

Matter is generally considered to be in one of the following states or phases: solid, liquid, gas, or plasma. Solids have a definite shape and a definite volume; the molecules are very close together. A block of wood is an example of a solid. What are some other examples of solids? (Tree, cars, books, etc.) Liquids have a definite volume, but take the shape of the container which they occupy. (At this point, you might want to show the same amount of H₂O - 30 ml or 3/4 cup with food coloring added - in a tall, thin container and then in a short, fat container to illustrate how the shape differs due to the container but the volume remains the same. An example of a liquid is water (H₂O). The next phase of matter is the gas which has no definite shape, thus shape is determined by the container occupied. Air is an example of gas; so is carbon dioxide. The fourth phase of matter, which may be new to you is called plasma. Plasma is very much like a gas because it, too, does not have a definite shape nor definite volume; however, plasma contains charged particles which allow it to conduct electricity unlike gases. Plasma is found in 99% of the universe since the stars, outer space, and the sun are composed of plasma.

1. Can two objects occupy the same space at the same time? (No)

2. Which phase are the following examples:

a. blood (liquid)

b. ice (solid)

c. carbon monoxide - smog (gas)

d. tea (liquid)

e. outer space (plasma)



This classroom connector addresses instructional objectives 1.06, 1.07, and 1.08

listening, observing, analyzing, constructing models

45 minutes to 1 hour

Playdoh, wire or coat hanger, needle and thread, glue, gumdrop, jellybeans, or colored marshmallows

Energy shell, electron, electron cloud, nucleus, neutron, proton

Yesterday, we talked about the structure of matter and its phases. Today we will learn about atoms which are tiny particles making up matter and the even smaller particles of which atoms are composed.

An atom is the basic unit of an element. It is composed of smaller subatomic particles. The central, dense core of an atom is called the nucleus. The nucleus contains positively-charged particles called protons and neutral particles called neutrons. Surrounding the nucleus are energy shells in which negatively-charged particles, called electrons, are located. Each shell can hold a different number of electrons. Because of this, all the shells together form an electron cloud around the nucleus.

An atom is neutral because it contains the same number of protons which are positive, and electrons which are negative. Since neutrons have no charge, it makes no difference how many neutrons an atom has, neutrons simply add weight to the atom.

Today we are going to construct a model of a simple atom using ordinary household items.

(Using a periodic chart on a wall or in a book, select several elements with small numbers of protons, electrons and neutrons. The atomic number of an element (number 1 through 109) is the number of protons an element has. Since the number of protons must equal the number of electrons, the atomic number is also the number of electrons. The atomic mass number {The decimal number often appearing under the symbol} is the sum of protons and neutrons. To determine the number of neutrons subtract the atomic number from the atomic mass number.

Example: Lithium has an atomic number of 3 and atomic mass number of 6.9 or 7 when rounded to the nearest whole number. Lithium has 3 protons, 3 electrons and 7-3 or 4 neutrons.

For this activity elements number 1-6 usually work well. If larger elements are selected, the model becomes too heavy to stand up.

Divide the class into small groups to construct several models. Assign each group an element to build with an accompanying chart showing the colors of gumdrops used for the protons, electrons, and neutrons.)

Now class, in order to construct your model, you must first make a circle out of your coat hanger leaving the hook attached. This will represent the energy shells where the electrons will be located. Stand the hanger up in a ball of playdoh attached to the table. Select one color of gumdrops to be electrons and count out the appropriate number.

Next, pick out a color of gumdrops for the protons and another color for the neutrons. Count out the appropriate number of each.

Using a large needle and thread, sew through each proton and neutron and tie the ends together to form the massive nucleus. This nucleus is to be attached to the coat hanger so that it will hang down in the middle.

Next, glue the electrons around the outside of the hanger. To complete your model make a key as follows:

proton electron neutron

(color of gumdrop) (color of gumdrop) (color of gumdrop)

Names of group members: (When each group has completed its model have the students look at the other models and try to identify the atom with looking at the key. Students will enjoy ending the class by eating the leftover gumdrops.)

1. What is the charge of a proton? (Positive)

2. Where are protons located? (Nucleus)

3. Do electrons have a charge? If so what? (Yes, negative)

4. Where are electrons located? (Energy shells)

5. Does the number of electrons matter? (Yes, must equal the number of protons)

6. Where is most of the mass of an atom? (Nucleus)

7. What is the charge of a neutron? (Neutral)

Every thing about us is composed of matter. Matter is composed of atoms which contain protons, electrons, and neutrons. Describe in a few sentences what you have learned about the structure of an atom, its subatomic particles, and their location in the atom.

energy shell - a spherical region surrounding the nucleus where electrons orbit.

electron - negatively charged particles located in energy shells outside the nucleus.

electron cloud - a three dimensional arrangement of energy levels containing electrons.

matter - anything which has mass and occupies space

neutron - neutral particles equal in size to the proton and also located in the nucleus

nucleus - small, dense core of an atom

phase - state or condition

proton - positively charged particles located in the nucleus of an atom

volume - space an object takes up

This is the time this file has been accessed since 04/02/98.

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