**Subject Area:**Science

**Grade:**8

**Body of Knowledge:**Physical Science

**Idea:**Level 2: Basic Application of Skills & Concepts

**Big Idea:**Properties of Matter - A. 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.

B. 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.

Clarification for grades K-2: The use of the more familiar term ‘weight’ instead of the term “mass” is recommended for grades K-2.

Clarification for grades 3-5: In grade 3, introduce the term mass as compared to the term weight. In grade 4, investigate the concept of weight versus mass of objects. In grade 5, discuss why mass (not weight) is used to compare properties of solids, liquids and gases.

**Date Adopted or Revised:**02/08

**Date of Last Rating:**05/08

**Status:**State Board Approved

**Assessed:**Yes

## Related Courses

## Related Access Points

## Related Resources

## Lesson Plans

## Original Student Tutorial

## Perspectives Video: Professional/Enthusiast

## Perspectives Video: Teaching Ideas

## Teaching Ideas

## Text Resource

## Unit/Lesson Sequence

## Virtual Manipulatives

## STEM Lessons - Model Eliciting Activity

In this MEA, students must select which material to use in the development of an advanced military scout robot. Students must analyze data about each material’s individual properties that would make it a valid choice for military or police service. Students must complete calculations to determine material density as well as the overall mass and weight of the robot. This lesson focuses on the characteristic properties of density, unit conversion, and differentiating between mass and weight.

Model Eliciting Activities, MEAs, are open-ended, interdisciplinary problem-solving activities that are meant to reveal students’ thinking about the concepts embedded in realistic situations. Click here to learn more about MEAs and how they can transform your classroom.

## Original Student Tutorials Science - Grades K-8

Learn to find the density (how many g/cm3) of three different objects, and explain what that number means with this interactive tutorial.

## Student Resources

## Original Student Tutorial

Learn to find the density (how many g/cm3) of three different objects, and explain what that number means with this interactive tutorial.

Type: Original Student Tutorial

## Virtual Manipulatives

Density is defined as mass per unit volume. Density of the gases is highly affected by the pressure and the temperature. This module simulates the measurement of the density of a gas sample. Different gaseous compounds and elements are available and the pressure and temperature of the sample can be adjusted. Learners will understand that density of an ideal gas can be doubled by doubling the pressure or by halving the temperature.

Type: Virtual Manipulative

This resource will build the following skills:

- Describe the relationship of mass and volume to density.
- Compare objects of same mass and different volume and vice versa.
- Explain that density of a certain object does not vary with its mass or volume.
- Measure the volume of an object from fluid displacement.
- Use density to identify an unknown material.

Type: Virtual Manipulative

Explore when objects float and when will they sink. Learn how buoyancy works with blocks by modifying the properties of the blocks and the fluid.

Some of the sample learning goals can be:

- Predict whether an object wills sink or float when place in a liquid, given densities of the object and liquid.
- Apply the definition of density to both liquids and solids
- Relate the buoyant force on an object to the weight of liquid it displaces
- Predict the weight of a completely or partially submerged object of known mass and volume
- Describe the forces that act on a completely or partially submerged object
- Explain how an object that is more dense than water can be kept afloat by placing it on an object that is less dense than water.

Type: Virtual Manipulative

## Parent Resources

## Perspectives Video: Teaching Idea

This science educator floats a teaching idea about neutral buoyancy and density.

Download the CPALMS Perspectives video student note taking guide.

Type: Perspectives Video: Teaching Idea

## Virtual Manipulatives

Density is defined as mass per unit volume. Density of the gases is highly affected by the pressure and the temperature. This module simulates the measurement of the density of a gas sample. Different gaseous compounds and elements are available and the pressure and temperature of the sample can be adjusted. Learners will understand that density of an ideal gas can be doubled by doubling the pressure or by halving the temperature.

Type: Virtual Manipulative

This virtual manipulative will help the students understand Archimedes' principle which states that the buoyant force is equal to the weight of the displaced fluid. This principle applies to both floating and submerged bodies and to all fluids. With this simulation, students will recognize that, if the body is less dense than the liquid it will float, whereas if a body is denser than the fluid, it will sink.

Type: Virtual Manipulative

This resource will build the following skills:

- Describe the relationship of mass and volume to density.
- Compare objects of same mass and different volume and vice versa.
- Explain that density of a certain object does not vary with its mass or volume.
- Measure the volume of an object from fluid displacement.
- Use density to identify an unknown material.

Type: Virtual Manipulative

Explore when objects float and when will they sink. Learn how buoyancy works with blocks by modifying the properties of the blocks and the fluid.

Some of the sample learning goals can be:

- Predict whether an object wills sink or float when place in a liquid, given densities of the object and liquid.
- Apply the definition of density to both liquids and solids
- Relate the buoyant force on an object to the weight of liquid it displaces
- Predict the weight of a completely or partially submerged object of known mass and volume
- Describe the forces that act on a completely or partially submerged object
- Explain how an object that is more dense than water can be kept afloat by placing it on an object that is less dense than water.

Type: Virtual Manipulative