Measuring MatterChapter 13Section 2

What do scientist use to measure matter?

What is the difference between weight and mass?

Standard Measurement System.

1. Metric System Metric

System– a system of measurements based on the number 10.

2. International System of Units (SI) – used to measure length, volume, mass, density, temperature and time.

Why is it important to use SI as the standard system of measurement:

•It allows scientist to compare data and communicate with each other about their results.

Unit of Measurement:

•Length: is measured in meters (m)

•Mass: is measured in Kilogram (kg)

•Weight – is the force of gravity acting on an object

•Volume: The amount of space an object takes up.

•Density: how much mass is contained in a given volume.

Weight:

•Is the measure of the force of gravity on an object.

▫Example: On Earth all objects are attracted toward the center of the planet by the force of Earth’s gravity.

Mass:

•The mass of an object is the measurement of the amount of matter in the object.

▫Example: If you travel to the moon your mass does not change

▫Questions: Would your weight change on the moon?

Why do scientists prefer to describe matter by its mass?

•Unlike weight, mass does not change with location, even when the force of gravity on an object changes.

Formulas: •Volume:▫ Volume =length x width x

height

•Density:▫Density = mass

volume* Because Density is

actually made up of two other measurements an object’s density is expressed as a combination of two unites (g/cm³ or g/ml)

VOLUME:

•The actual amount of space that matter occupies.

•Common units of Volume . . .▫Liter (L)▫Milliliter (mL)▫Cubic Centimeter (cm³)

Density:

• relates the mass of a material in a given volume.

•Objects with _________ densities than that of water will sink.

•Objects with _________ densities than water will float.

Using Density

Density is a ___________ property of a substance. (physical or chemical)

Because of this, density can be used in ________ an _________ substance.

Unit of Measurement:

•Time: The seconds (s) is the SI unit used to measure time.

•Temperature: Celsius (C) scale is used along Kelvin (K)▫Converting

Fahrenheit to Celsius Subtract 32 from F

temperature. Then multiply the result by 5 and divide by 9 F-32x5/9

Summarize Unit of Measurements (SI)

•Left Hand Activity:

▫Use pictures to depict meaning of terms: (length, mass, weight, volume etc.)

NO WORDS!! NO FORMULAS!! NO ABBREVATIONS (I.E. LETTER)