The Properties of Matter

1. The Properties of Matter What is 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. The volume in a solid is always expressed in cubic units. Cubic means having “three dimensions.” Cubic meters(m3) or cubic centimeters(cm3) are most often used to express the volume of a solid. The 3 in m3 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? __________ Solid Volume

5. The Volume of Solids, Liquids, and Gases • 1 mL = 1 cm3REMEMBER 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 it, so how do you measure it? ex: balloon

6. 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…_________________. Matter and Mass

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.

8. So, what about weight? • 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. 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. The major differences between

11. Describing Matter • Knowing the characteristics or properties of an object can help you identify the object. • There are: • Physical Properties • Chemical Properties

12. 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…

13. 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

14. 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.

15. Some Characteristic Properties • So which properties allow us the identify unknown substances? • Density • pH • Solubility • Melting and boiling points • Etc…

16. 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.

17. If Density = mass/volume • Then mass = volume x density or m = v x d • AND volume = mass/density or volume = m V

18. Spotlight on Solubility Solubility is the maximum amount of solute that can be dissolved in a given amount of solvent Can be measured in g/L Solubility depends on temperature Solubility of gas in water

19. Other Characteristic Properties • Solids: electrical conductivity & flame test • Liquids: reaction to litmus & cobalt chloride paper • Gases: reaction with glowing splint, burning splint & limewater

20. Gas Tests • Oxygen • Hydrogen • Carbon dioxide

21. 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.

22. 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

23. Clues to chemical changes • Color change • Fizzing or bubbling (gas production) Not to be confused with boiling! • Heat • Production of light, sound, or odor. • Chemical changes are not usually reversible!