The Material World

1. The Material World Properties of Matter

2. Properties • There is material all around us. This could be natural or synthetic (manmade) • These materials are distinguished from one another by their properties. • It is these properties that will determine how different materials will react with one another. • For example: Oil and water or salt and water.

3. Characteristic Properties • Property: information used to describe a substance. • There are physical properties; properties we can observe without changing the material. • Chemical properties; describes how substances react with one another.

4. Characteristic properties can be both physical or chemical. These properties are: • Color • Texture • Taste • Shape • State (gas, liquid, solid) • Ductility & Malleability • Melting and boiling point • Density • Use or need

5. Mass and Volume • To measure the volume of a liquid simply read the measurement off of a graduated cylinder. • NOTE: be sure to read the bottom of the meniscus. Volume is the amount of space taken up by an object

6. Volume of a cube: V= s x s x s (All sides of a Cube are equal) S S S Volume of a rectangular prism: V= l x w x h h w l

7. To measure the volume of an irregular shaped object, ex: rock, use the water displacement method. • Water displacement method: • Fill a graduated cylinder with a known quantity of liquid. • Place the object in the cylinder • Follow this formula V= Vf(water with object) – Vi (just water)

8. Mass is very easy to calculate. • Simply place the object on a scale or balance. • Use of the triple beam balance will be explained in the lab.

9. Example Problems • Volume of a cube with a side of 3.5 cm. • Volume of a rectangular prism with a length of 7cm, width of 4cm, and height of 1.5cm • Volume of a rock that raised the water in a graduated cylinder(GC) 4ml from the original 15ml.

10. Density • Mass and volume are not considered characteristic properties. • This is due to the fact that many objects could have the same mass and volume. • In these cases one would have to calculate the density of the objects. • Density: measures the amount of matter (particles or stuff) in a substance.

11. To calculate the density of an object one must know the mass and the volume. • Density is calculated using the following formula: D = m/v • The formula reads density is equal to mass divided by volume. • The units for density are g/ml

12. Example problems • Density of an object with a mass of 10g and a volume of 2ml. • Density of a substance with a mass of 100g and a volume of 20ml. • Density of a cube with a mass of 40g and a side of 2cm. • Density of a bracelet with a mass of 12g and raised the water in a GC 2ml from 20ml.

13. Temperature • Temperature: is the measurement of the degree of agitation of the particles that make up a substance. • This means when a substance is heated the particles begin to move around. • This movement causes heat. • The faster the particles move the higher the temperature. • A substance cools down when the particles are less agitated.

14. States of Matter • A state is the form in which matter can be found. • There are three states; • Solid: ice, wood, salt, sugar • Liquid: water, mercury, vinegar • Gas: steam, methane, propane • Some substances can be found in all three states. Ex: water

15. Acidity and Alkalinity • pH is the measure of how acidic or how basic (alkalinity) a solution is. • pH scale measures solutions (liquids) • The pH scale has a range of 0-14. • If a solution falls into the 0-7 range it is an acid, 7-14 it is a base (alkaline). • 0 = battery acid, 14 = drain cleaner • If a solution is 7 it is neutral ex: pure water.

16. Changes in Matter • There are two types of changes. • Matter: anything that has mass and occupies space. Stuff that makes up a substance • Physical changes: occurs when the appearance of the substance is changed only. • Chemical changes: when two substances interact to create a new substance.

17. Physical Changes • All of a substance’s chemical makeup stays the same. • Examples: • A broken dish • Paper torn in two • Broken mirror • Ice melting • Ground coffee • Shredding cheese

18. Chemical Changes • There are four simple signs that a substance is undergoing a chemical change. • Change in color: metal rusting, fruit going bad, etc. • Formation of a gas (you will see bubbles/foam): baking soda and vinegar, antacid and water.

19. 3) Formation of a precipitate: creates a solid at the bottom of the mixture that does not dissolve. • Example: Too much chocolate powder in milk. 4) Energy change: a substance will give off or release energy. This usually results in a temperature change. • Example: salt and ice, ice packs.

20. Conservation of Matter • Law of Conservation of matter states: • The quantity of matter or total mass of a closed system will remain constant regardless of the process that takes place within the system. • This includes chemical reactions and physical changes. • Example: if ice melts in a sealed container it will have the same mass.

21. Mixtures • A mixture is a substance that contains more than one type of particle. • For example: salt and water, vinegar and baking soda. • Homogeneous mixtures: substances whose parts are completely mixed together (fully dissolved) • Examples: salt and water, tea, coffee, lemonade, ice tea

22. Heterogeneous mixtures: substances whose particles are not fully mixed together (not dissolved) • Examples: water and sand, oil and water.

23. Solutions • A solution is a homogeneous mixture (particles are fully dissolved). • A solution has two parts. • Solute: substance being dissolved (ex: salt) • Solvent: substance doing the dissolving. (ex: water) • Solutions can be saturated solvent can not dissolve any more solute

24. A solution becomes saturated when too much solute poured into a solvent. • Solutions can also be unsaturated solvent can dissolve more solute. • What are some examples of heterogeneous mixtures? • What are some examples of homogeneous mixtures? • Provide some examples of saturated and unsaturated solutions.

25. Separation of Mixtures • The separation of different mixtures is not always an easy task. • For heterogeneous mixtures this process is quite simple. • Simply remove the solid or the lighter (less dense) substance. • For example: oil and water or sand and water.

26. For homogeneous mixtures the process is slightly more complicated. • There are five techniques that one could use to separate mixtures. 1) Filtration: a process that separates the parts of a mixture by retaining large particles and letting smaller one pass through. • Example: making coffee, filtering cooking oil, a screen over a window.

27. 2) Hand- pressing: process that extracts a liquid from a mixture using manual force (by hand). • Example: squeezing juice from a fruit or vegetable, making oil. 3) Sedimentation: process that consists of allowing solid particles to settle at the bottom of a motionless mixture. • Example: paint sitting on a shelf, salad dressing

28. 4) Drying: process that uses evaporation by heat to remove water from a mixture. • Example: Removing salt from water, removing alcohol from wine. 5) Grinding: process that reduces a solid into very small particles by either crushing or cutting. • Example: making wine, making jam

29. Elements • Different objects are composed of different substances. • Characteristic properties allow us to tell different substances apart. • Substances are made up of elements . • Elements are the basic units (smallest parts) that compose all matter. • These elements could be solids, liquids and gas.

30. The Periodic Table • In 1865 a Russian chemist, Dimitri Mendeleev created a way of classifying elements. • He would classify these elements in a table according to their properties. • The first periodic table created in 1869 contained only 63 elements. • Today there are over one hundred elements in the table.

31. The Periodic table has elements in individual squares arranged in columns and rows. • Each square contains the element symbol, name and number. • The numbers increase from left to right. • The first row contains two elements only. • Rows 2 and 3 contain six. • The table also contains the atomic weight of each of these elements.

32. Atoms • An atom is the smallest unit of matter. • All known atoms are classified in the periodic table. • Most periodic tables will provide several pieces of information. • The most important is the chemical symbol. Ex: Hydrogen = H • These symbols are universal. Ex: In Germany Hydrogen= Wasserstoff = H

33. All elements are pure substances. • Therefore, the periodic table shows all known elements which are pure substances. H=hydrogen He=helium Li=lithium Be=beryllium B=boron C=carbon N=nitrogen O=oxygen F=fluorine Ne=neon Na=sodium Mg=magnesium Al=aluminum Si=silicon P=phosphorous S=sulfur Cl=chlorine Ar=argon K=potassium Ca=calcium

34. All Atoms have two major parts the nucleus and the electrons. • The electrons revolve around the nucleus, like planets revolve around the sun. • Inside each nucleus there are protons and neutrons.

35. Molecules • Elements are pure, therefore they are not mixed with any other substances. • Atoms are the smallest part of an element. • When two or more elements get mixed together it becomes compound (mixture). • A molecule is the smallest part of a compound. Ex: Water= H2O, Salt=NaCl

36. Reading Compounds • As mentioned above the smallest part of an element is an atom. • Since an element is a pure substance it will only have one part (no mixture). • A compound is a mixture of two or more elements. • Therefore, a compound has more then one part.

37. The smallest part of a compound is a molecule. • A molecule is made up of two or more atoms. • When reading a compound you will be able to see how many of each atom is present. • For example: H2O has 2 Hydrogen atoms and 1 Oxygen. • To read this you must look at the number directly after the atom.

38. If there is no number it is understood that it is a 1. • Example: C2H4 This molecule has 2 Carbon atoms and 4 Hydrogen atoms. • Complete the following examples: • H2SO4 • CH4 • NaOH • BeF2O6 • Mg2He3 • Ca(OH2)3

39. If there is brackets, you must multiply all of the numbers on the inside of the brackets by the number on the outside. • Ex: Ca(OH2)3 Has 1 Calcium, 3 Oxygen, and 6 Hydrogen. • H3(Be3F2)4 • Na(O2Ne2)2 • He6(C2)3 • O(H3F)2 • N5(H2F3)4

40. Drawing Atoms and Molecules • The first step you must determine how many of each atom is present. • Ex: H2O has 2Hydrogen and 1 Oxygen • Next you have to draw circles that correspond to each of the atoms identified. Be sure to label. H O H

41. Motion • Motion: is the change of position or location over a certain length of time. • Basically motion is the movement of an object. • Motion is the result of an applied force. • In Physics motion is usually measured in terms of velocity and speed.

42. For an object to move there must be a force that is applied to it. • No object can move on it’s own. • An object that is not moving is said to be at rest.

43. Types of Motion • There are three types of motion. 1)Translational Motion • This is the when an object moves in a straight line. Ex: Car, bike 2) Rotational Motion • This is when an object moves in a circle. Ex: Merry-go-round, wheel 3) Spiral Motion • This is when an object moves in spiral. Ex: Cork screw, screw

44. Force • In Physics a force is any action that allows an object to move. • Ex: pushing a shopping cart • A force can also change the speed or direction (trajectory) of an object that is already in motion. • Ex: curling, pool, bocce • Finally a force can deform (change the shape) of an object. • Ex: stretching an elastic, leggings

45. Types of force • There are five types of force 1) Tension • This force will stretch an object • Ex: bow and arrow, elastic

46. 2) Compression • This force will compress (squeeze) an object. • Ex: squeezing a sponge, crushing a can

47. 3) Torsion • This force will twist an object • Ex: opening a jar, twisting your ankle.

48. 4) Flexion • This is the force that will bend an object. • Ex: your spine, pole vault

49. 5) Shearing • This is the force that will tear an object. • Ex: tearing a piece of paper, earthquake

50. Effects of a Force • As mentioned above an object needs a force to move. • No object will move on its own. • Therefore, the effects of a force is motion. • Even the human body is a complex system of forces. • In one movement the human body can experience all five forces.