# Properties of Matter

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1. Chapter 2 The Properties of Matter What is matter? Which part of this course is more concerned with matter?
2. Matter
• Everything is made of MATTER!
• Matter is anything that has volume and mass.
• Volume is the amount of space an object takes up, or occupies.
3. Measuring the volume of liquids
• Liquids have volume. We measure that volume with a graduated cylinder.
• Notice the meniscus in the graduated cylinder.
• Always measure at the bottom of the meniscus!
• A liquid in any container has a meniscus.
• Liters (L) and mL (milliliters) are most often used to express the volume of liquids.
4. Solid Volume
• The volume in a solid is always expressed in cubic units.
• Cubic means having “three dimensions.”
• Cubic meters(m 3 ) or cubic centimeters(cm 3 ) are most often used to express the volume of a solid.
• The 3 in m 3 signifies that three quantities were used to get the final result. (That is a derived quantity!)
• If each side in the cube below is 2m, what is the volume of the cube?
• __________
5. The Volume of Solids, Liquids, and Gases
• 1 mL = 1 cm 3 REMEMBER THAT!
• That is why you can compare the volume in liquids to solids.
• How do you measure the volume of a gas?
• You can’t see, so how do you measure it?
• ex: balloon
• _________________________
6. Matter and Mass
• What is mass?
• Mass is the amount of matter that something is made of.
• Even atoms have mass!
• Looking at the picture…
• The mass stays constant in certain forms of matter such as…__________________.
• The mass changes in certain forms of matter such as…_________________.
7. What is the difference between mass and weight?
• This is an important concept to understand!
• Let’s start by understanding gravity.
• Gravity is the force of attraction between objects that is due to their masses.
• All matter experiences gravity!
• The amount of attraction between two objects depends on their weight.
• There is attraction between all objects with mass, but since they are so small in reference to the earth, the attraction between them is also small.
• Weight is the measure of the gravitational force exerted on an object!
• Look at Spot and the rock…which one is attracted to the earth more through gravitational force? ________________
• Which one weighs more? ___________
• So, this means the greater the gravitational force, the greater the weight.
• Which weighs
• more? ------->
9. Measuring Weight and Mass
• The SI unit for mass is kilogram (kg).
• Sometimes we will use milligrams or grams. (mg or g)
• The SI unit for weight (or gravitational force) is NEWTONS.
• A Newton is approximately equal to the weight of a 100 gram mass on earth.
10. The major differences between
• MASS
• A measure of the amount of matter in object.
• Always constant, no matter the location.
• Measured with a balance.
• Expressed in kilograms, grams, and milligrams.
• WEIGHT
• A measure of the gravitational force on an object.
• Varies depending on where the object is in relation to the earth. Example: ____________
• Measured with a spring scale.
• Expressed in Newtons.
11. Mass is a measure of Inertia
• What in the world is inertia?
• Ever try to move a car? Yeah, it is difficult!
• That is because of inertia!
• Inertia is the tendency of all object to resist a change in motion.
• This will cause objects that are still to remain still, and allow objects that are moving to continue moving.
• Mass is a measure of inertia because the greater the mass of an object…the more difficult it is to move.
12. Describing Matter
• Knowing the characteristics or properties of an object can help you identify the object.
• There are:
• Physical Properties
• Chemical Properties
13. Physical Properties
• Things that describe the object are physical properties.
• Physical properties can also be observed or measured without changing the identity of the matter.
• Examples of physical properties include: color, odor, size, state, density, solubility, melting point, etc…
14. Spotlight on Density
• Density is a very helpful physical property.
• Density = mass per unit of volume or Density = mass/volume
• Density is an excellent help in identifying substances because each substance has its own density.
15. If Density = mass/volume
• Then mass = volume x density
• or
• m = v x d
• AND volume = mass/density
• or
• volume = m
• V
16. Chemical Properties
• Chemical properties describe a substance based on its ability to change into a new substance with different properties.
• Ex: wood burns to form ash and smoke
• Chemical properties cannot be observed with your senses.
• Chemical properties aren’t as easy to observe as physical properties.
• Examples of chemical properties: flammability and reactivity
17. Characteristic Properties
• The properties that are most useful in identifying a substance are its characteristic properties.
• Remember the difference between physical and chemical properties.
• Physical properties can be observed! (with your eyes!) IDENTITY OF SUBSTANCE DOES NOT CHANGE!
• You can observe chemical properties only in situations in which the identity of the substance could change.
18. Physical Changes
• A physical change is a change that affects one or more physical properties of a substance.
• Physical changes do not form new substances! EX: ice melting or sugar dissolving
• Physical changes are easy to undo.
19. Chemical Changes
• A chemical change occurs when one or more substances are changed into entirely new substances with different properties.
• You can observe chemical properties only when a chemical change might occur!
• Examples of chem. changes:
• baking a cake
• rusting
20. Clues to chemical changes
• Color change
• Fizzing or bubbling (gas production)
• Heat
• Production of light, sound, or odor.
• Chemical changes are not usually reversible!
21. For tomorrow…