Unit II: Measurement of Matter

Metric System: A system of measurement based on the number 10 Parts of the Metric System Parts of the Metric System Length Length Mass Mass Volume Volume Density Density

WHY DO WE USE THE METRIC SYSTEM? Almost all other countries are using the metric system Other countries’ companies are refusing to buy products from the U.S. if not labeled in metric units Scientists need a universal way to communicate data (SI Units)

Length: distance between two points Meter: Meter: about the length of a yard—length of your leg (m) about the length of a yard—length of your leg (m) Centimeter: Centimeter: about the width of your pinky finger (cm) about the width of your pinky finger (cm) Millimeter: Millimeter: about the thickness of a dime (mm) about the thickness of a dime (mm) Kilometer: Kilometer: a little less than mile (km) a little less than mile (km)

The longer lines on the metric ruler are called … centimeters centimeters

The shorter lines on the metric ruler are called … millimeters millimeters

There are…… 10 millimeters in 1 centimeter 10 millimeters in 1 centimeter 100 centimeters in 1 meter 100 centimeters in 1 meter 1,000 millimeters in 1 meter 1,000 millimeters in 1 meter 1,000 meters in 1 kilometer 1,000 meters in 1 kilometer

10.5 cm 10.5 cm 105 mm 105 mm Measure the turtle from the rear of its shell to the tip of its nose. Record its length in both centimeters and millimeters.

Measure the Lines in cm & mm

To Earn Extra Credit, make…. Chocolate Chip Cookies! 2 ¼ Flour 1Baking Soda 1Salt 2Butter ¾ Sugar 1Vanilla 2Eggs 2Chocolate Chips

What’s the point……. Don’t forget UNITS or no one will understand what you mean!!!

When writing numbers….. They must be written to the nearest 10 th and the correct units!!!! They must be written to the nearest 10 th and the correct units!!!! Length = 10 Written as 10.0 cm Length = 10.3 Written as 10.3 cm

Mass: the amount of matter (“stuff”) an object contains **MASS DOES NOT CHANGE AS YOU MOVE FROM PLACE TO PLACE—it only changes if you get bigger or smaller! Gram: about 1 M & M (g) Kilogram: about 2 pounds (kg) **there are 1,000 grams in a Kilogram

Mass Lab Name of Item Mass Unsharpened Pencil Blue Calculator with Cover Glue Stick Chem Plate Agenda Safety Glasses Rubber Stopper GPS Unit Beaker Scissors

Weight: measure of pull of gravity of an object. **THIS WILL CHANGE AS GRAVITY CHANGES! Pounds (lbs) Pounds (lbs) **the bigger the planet, the bigger the gravitational pull = more weight **the bigger the planet, the bigger the gravitational pull = more weight

How much do you weigh…..

Volume: amount of space an object takes up Regularly Shaped Solids (square / rectangle) Regularly Shaped Solids (square / rectangle) Length x Width x Height (cm 3 ) Length x Width x Height (cm 3 ) Liquid: Liquid: Liters (l) Liters (l) Milliliters (mL) Milliliters (mL)

What is used to measure liquid volume … Graduated cylinder. Graduated cylinder. Goes up by 1 mL Meniscus (curve—read bottom!)

What is density? Density: how much “stuff” (mass) is in a certain volume (amount of space) Density: how much “stuff” (mass) is in a certain volume (amount of space) …but what does that mean??? All matter is made up of tiny All matter is made up of tiny particles moving around—the more particles, the more mass

When you measure density, you are measuring how many tiny particles are in a given space When you measure density, you are measuring how many tiny particles are in a given space Density = Mass Volume Volume Density Units: g/cm 3 or g/mL Density Units: g/cm 3 or g/mL

How does the density of an object determine if it will float or sink? Objects with LESS DENSITY float in things that have greater density Objects with LESS DENSITY float in things that have greater density The density of water 1.0 g/mL—meaning any object with a density GREATER than 1.0 g/mL will SINK! The density of water 1.0 g/mL—meaning any object with a density GREATER than 1.0 g/mL will SINK! >1.1 g/mL 1.0 g/mL.9 g/mL.5 g/mL.1 g/mL

DENSITY DOES NOT CHANGE IF YOU CUT AN OBJECT IN HALF!!

Why do Hot Air Balloons Float? Because hot air is less dense than cold air…….. Because hot air is less dense than cold air…….. But why??? It has to do with the Kinetic Theory of Matter: all matter (stuff) is composed of tiny particles in motion.

Phase Position of Particles Particle Motion Picture Solid Close together with a definite shape and volume Slow Liquid More spread out without a definite shape but a definite volume Medium Gas Very far apart with no definite shape or volume Fast

So…Why do Hot Air Balloons Float? When air is heated, the particles move faster and spread out—making less “stuff” in the same amount of space. When air is heated, the particles move faster and spread out—making less “stuff” in the same amount of space. Less Density!