Matter & Energy

1. Matter & Energy Ms. Fisher 2012

2. Chapter One Notes Section 1.1 • Matter makes up all objects and living organisms in the universe. • Matter is anything that has mass and takes up space. • Examples of matter: you, your desk, chocolate, zombies, venti chai tea lattes from Starbucks, your dog, the air you breathe, and even though you think your siblings “do not matter”, they are matter too!

3. Not everything IS matter. For example, light and sound to not have mass or take up space, so they are not matter. • Matter is made of particles called “atoms”. • Atoms are too small to see. • Mass is a measure of how much matter an object contains. Some objects have more matter than others, therefore, they have more mass...but you already know that. (‘Cause you’re a genius!)

4. Which has more MATTER? (Why?)

5. Measuring Mass • The standard unit of mass is the kilogram for large masses and gram for small masses. • There are 1000 grams in one kilogram. (Kilo means “thousand” so KILO-gram means “thousand grams”. • There are different ways to measure mass. • A pan balance compares the mass of two objects. • -A triple beam balance compares the mass of an object with a standard mass on the beam.

6. Types of Balances Triple-Beam Balance Pan balance

7. Measuring Weight • Weight is the downward pull of an object due to gravity. • Weight is measured using a scale. • A spring scale (shown on p.11), tells how hard on object is pulling or pushing on it. • The standard scientific unit for weight is the newton (N), the common unit is the pound (lb)

8. Spring Scale

9. Mass and weight are closely related, but are not the same. • Mass describes how much matter an object has, weight tells how strongly gravity is pulling on that matter. • A one kilogram object has a weight of 9.8 newtons, or 2.2 pounds.

10. Measuring Volume • Volume is the amount of space an object takes up. • Volume for solid objects is measured in cm3 or m3 • Volume can be calculated using a formula, such as V=lwh. • Volume can be calculated using displacement. • Remember liquids are measured in mL. • 1 mL is equivalent to 1 cm3

11. Chapter One NotesSection 1.2 • Matter is made of atoms. • Atoms are the smallest basic units of matter. • Atoms are extremely small. • An atom has a radius of approximately 10-10 meters. • Atoms have mass. • A teaspoon full of water has approximately 5 x 1023 atoms. • A teaspoon full of water is about 5 grams. • To find the mass of a single atom you would have to divide. • (even though the number is really small, it does prove that atoms have mass)

12. Atoms are like the “building blocks” of all matter. • For example, imagine a single LEGO in a large castle structure. • The castle has a foundation, moat, bridges, and towers that make it up, but the smallest thing it can be broken down into is a single LEGO. • Scientists have identified more than 100 kinds of atoms.

13. Atoms combine to form molecules. • A molecule can be made from two or more of the same or different kinds of atoms. • For example, water molecules are made up of hydrogen and oxygen. • Ozone molecules are made up of only oxygen atoms. H H O

14. Changing the type of atom, or the ratio of atoms, changes the substance entirely. • For example, two oxygen atoms bonded together gives us oxygen gas. Three oxygen atoms bonded together gives us Ozone, which has different properties from oxygen gas.

15. Atoms and molecules are always in motion. • You can see evidence of moving air molecules as they collide with dust or other particles in the air. • You can see liquids move when you add a drop of food coloring to water. • Even the atoms and molecules in a solid constantly vibrate.

16. Section 1.3 • Matter combines to form substances • Matter that contains only one kind of atom or molecule is pure. • Matter often contains two or more substances mixed together. • Substances can be composed of elements, compounds, or mixtures. • An element is a substance that contains only one kind of atom. • Elements cannot be broken down into any other substance by chemical or physical means. • Gold is an example of an element.

17. A compound is a substance that consists of two or more different types of atoms bonded together. • Water molecules are an example of a compound. • Water molecules contain two kinds of atoms bonded covalently (sharing electrons). • A molecule of oxygen is not a compound. • Some compounds, such as table salt, are bonded ionically (transfer of electrons). • The properties of a compound may differ from the individual properties of the elements that make them up. • For example Na (poison) + Cl (poison) = table salt (YUM)

18. A mixture is a combination of different substances that retain their individual properties and can be separated by physical means. • Parts of mixtures can be the same or different throughout. • Mixtures can be either heterogeneous or homogeneous. • A heterogeneous mixture has different properties in different parts of the mixture because the substances in different parts of the mixture vary. • An example of a heterogeneous mixture is Italian salad dressing.

19. A homogeneous mixture has substances evenly spread out throughout the mixture. • Some types of homogeneous mixtures are called solutions. • An example of a solution is salt water.

20. Section 1.4 • Matter exists in different physical states. • Particle arrangement (how close or far apart) and motion determine the state of matter. • States of matter are the different forms in which matter can exist. • The three states are: solid, liquid, and gas. • Ice, water, and water vapor are examples of the different states of matter of the molecule H2O • The state of a substance depends on the space between its particles and the way the particles move.

21. There is a general rule that applies to most objects’ states of matter: the particles in gases are farthest apart, liquids in between, and solids closest. • Water is an important exception to this rule; the particles in a solid are actually farther apart in a solid than in a liquid. • This makes ice float.

22. Now Presenting…. SOLIDS

23. A solid is a substance with a fixed volume and shape. • The particles in a solid are close together and the particles can vibrate. • The particles in some solids, such as table salt or ice, occur in a regular pattern. • Example: the molecules of ice are in a hexagonal pattern. • When is this hexagonal pattern visible?

24. Now Presenting…. Liquids

25. A liquid has a fixed volume but not a fixed shape. • Liquids take the shape of containers they are in. • Particles in a liquid are attracted to each other, but can move from one place to another. • This is why liquid can flow.

26. Now Presenting…. Gases

27. A gas has no fixed volume or shape. • Gases can take on both the shape and volume of a container. • The particles are not close and can move in any direction. • The space between gas particles can change with changes in temperature and pressure.

28. Gas Composition • The molecules in a gas are very far apart compared to a solid or liquid. • The amount of space between molecules can change easily. • Rigid-cannot change shape • If more air is pumped into a rigid container, the volume of the gas does not change; the molecules just become more packed.

29. Imagine it being the same as if you have 20 people in a class, and then 5 more come in tardy, the size of the room does not change to accommodate the tardy people. • If the container holding the gas is opened, the molecules with spread out and mix with the air outside. • At the end of the period, the door opens and students (molecules) leave and mix with the students outside.

30. Gas Behavior (p. 33) • Gas molecules are in constant motion and hit each other and the edges of the container they are in. • The more gas molecules you have in a container, the more pressure you will feel on the outside of the container. • Imagine filling a bike tire. With little air, the tire feels squishy. If you pump more air in, it gets harder. • The speed gas molecules move depends on the temperature of the gas. • Gas molecules move faster at higher temperatures. • If you put a helium balloon in the fridge, it will shrink!

31. If you increase the pressure of a gas and leave the temperature constant, the volume will decrease. • If you increase the temperature of a gas and leave the volume constant, the pressure will increase. • If you increase the temperature of the gas and leave the pressure constant, the volume will increase.

32. Chapter Two Notes • Matter has observable properties. • Physical properties describe a substance. • Physical properties of a substance can be observed without changing the identity of a substance. • Density, mass, color, size, volume, and texture are examples of physical properties. • Any change in a physical property of a substance is a physical change. The identity of the material remains the same during the change. • Example of a physical change include: cutting a material, breaking it, and changing its state.

33. Density is the relationship between the mass and the volume of a substance • Calculate density by dividing mass by volume. • Example: A glass marble has a volume of 5 cm3 and a mass of 13 g. What is the density of the glass? • What do you know? • What do you want to find out? • Write the formula. • Substitute into the formula. • Calculate and simplify.

34. Chemical properties describe how substances form new substances. • To observe chemical properties in a substance, you must see a chemical change. • To observe the combustibility of a piece of paper for example, the paper must burn. • The products that result from burning the paper differ in identity from the paper itself.

35. A chemical change occurs when elements and compounds that make up a substance rearrange to form new material. • The end materials are chemically different from what you started with. • A chemical change occurs when something unpredictable happens. • Signs of a chemical change include burning, rusting, production of an odor, a gas or a solid (precipitate), and any unpredictable change in temperature, color, or state. • Other examples of chemical properties include reactivity, tendency to corrode, and toxicity.

36. Review Questions! • If you put bread, peanut butter, and jelly together, and made a PBJ sandwich, would this be an example of a physical or chemical change? • If you put bread, peanut butter, and jelly together and it miraculously resulted in a grilled cheese, would this be an example of a physical or chemical change? • If you mix blue and yellow and got green as a result, would it be an example of a physical or chemical change? • If you mixed blue and yellow and got purple as a result, would it be an example of a physical or chemical change? • If you put a melted Blizzard (from DQ) in the freezer and it becomes a solid, is this an example of a physical or chemical change? • If you mix two liquids and the mixture starts to become chunky, is this a physical or chemical change?

37. Chapter Two NotesSection 2.2 • Changes of state are physical changes. • Matter has three common states- solid, liquid, and gas. • Matter can change from one state to another. • A solid has a fixed volume and a fixed shape. • A liquid has a fixed volume but can assume the shape of its container. • Both the volume and shape of a gas depend on the volume and shape of the container.

38. Solids can become liquids and liquids can become solids. • When a substance melts, added energy as heat breaks the tight bonds between particles. • This process occurs at a temperature called the melting point of the substance. • The melting point of water is 0°C. • For some substances, the melting point is not a well-defined temperature.

39. Freezing is the process by which particles of a liquid lose energy and bond tightly to form a solid. • The freezing point of a substance is the same as its melting point. • The freezing point of water is therefore, 0°C. • While a substance with a well-defined melting point is freezing or melting, the temperature will not change.

40. Liquids can become gases and gases can become liquids. • During condensation, a gas is changed to a liquid. • Energy is removed from the gas, and the particles from loose bonds. • High-energy particles can escape from the surface of a liquid by evaporation. • If energy as heat is added to a liquid, bubbles of gas can form throughout the liquid in a process called boiling. • The boiling temperature of water is 100°C.

41. Solids can become gases and gases can become solids. • Sublimation is the process by which solids become gases, and deposition is the process by which gases become solids. • Sublimation and deposition can happen only under certain pressure and temperature conditions.

43. Review • The particles in a solid are______________________________________. • The particles in a liquid are _____________________________________. • The particles in a gas are _______________________________________. • What will happen to the pressure of a gas if you increase the temperature? • What will happen to the volume of a gas if you increase temperature? • What will happen to the volume of a gas if you increase the pressure and temperature stays constant? • Name three examples of different types of physical changes and three examples of different types of chemical changes. Physical Chemical Calculate the density of a liquid that is 16 cm3 and 12 g.

44. Section 2.3 • Substances have characteristic properties, and those properties are used to identify substances. • When you reach into your pocket, you can identify a coin based on size: dimes are smallest, quarters are largest. • Imagine you see a glass of a white liquid in front of you. You might hypothesize that it is milk. Before you get too excited, remember it is an unknown substance, so you should not taste it. You might observe and measure such properties as: color, odor, texture, density, boiling point, and freezing point. A few of these properties might help you realize that the glass actually contains glue-so put the Oreos away!

45. Although a substance may share properties with another substance, no two substances have identical sets of properties. • The following properties can be used to identify substances because they are the same for every sample of a particular substance: • Density- compare the density of the unknown substance with the density of a known substance such as wood, plastic, or steel. • Heating properties- some substances heat up quickly, while others take much more time. • Aluminum and iron conduct heat while, which is why they are good materials for pots and pans. House insulation materials are poor heat conductors, which is why your house is able to stay warm and cozy inside on a cool day.

46. Solubility- solubility is a measure of how much of a substance dissolves in a given volume of a liquid. • Sugar and dirt have very different solubilities. If you put a spoonful of sugar into water and stir, it will dissolve quickly. If you do the same thing with dirt, it will probably just settle at the bottom. • Conductivity- Some substances allow an electric charge to run through them better than others. • Copper wire is a good conductor, while rubber and plastic will block the flow of a charge. • Magnetic properties- some substances can be picked up by a magnet, while others cannot. • Iron, cobalt, and nickel are magnetic, but copper, aluminum, and zinc are not.

47. Mixtures can be separated by using the properties of the substances in them • Substances can be separated by using differences in physical properties. • A magnet will separate materials that have magnetic properties from those that don’t. • Magnets are used at recycling centers to separate aluminum and steel (which is magnetic)

48. Filtration can separate solids from liquids and also separate solids that differ in particle size. • Imagine drinking tea or coffee without using a filter to block out the tea leaves or coffee grinds! • Filtration is important because it keeps the water you drink safe! • Water filtration includes three steps: • Add a chemical to the water that causes larger particles to stick together. These particles settle to the bottom where they can be removed. • Run the water through molecular filters, which help to remove even smaller particles. • Add chlorine to disinfect the water and make it safe to drink. • Evaporation can separate a liquid and the substances dissolved in it.