2. Atoms & The Periodic Table of Elements

3. History first… Alchemy Robert Boyle John Dalton Dmitri Mendeleev Jons Berzelius

4. Alchemy: one of the earliest forms of chemistry. Scientists try (unsuccessfully) to turn metals of low value (iron or lead) into gold. Though they were unsuccessful, they contributed knowledge to the chemical world. For example how changes affect matter.

5. Today, Chemistry is the study of matter, including its properties, composition, and the changes it undergoes.

6. It’s About Matter! Matter- Anything that takes up space and has mass. (ex., Pizza and Air)

7. Robert Boyle… Considered the first real chemist. He introduced the first definition of an element as a pure substance that cannot be broken into simpler substances by chemical means.

8. John Dalton… introduced the idea that each element was made up of a different kind of atom.

9. Atomic Structure… An atom is made up of three basic parts: protons, neutrons, and electrons. The protons which have a positive charge [+] and the neutrons which have no charge, form the nucleus in the center of the atom. The electrons which have a negative charge [-], move sporadically around the nucleus.

10. Draw this model on your paper

11. Electrons are negatively charged particles that have a very low mass. There are an equal number of electrons as there are protons. Protons are positively charged particles found in the nucleus. There are an equal number of protons as there are electrons.

12. Neutrons, also found in the nucleus, have no electrical charge. They are neutral. They have about the same mass as a proton. The nucleus is the central core of an atom that contains most of the mass of an atom because it contains both the neutrons and protons.

13. Each atom has an equal number of protons and electrons. Because the negative charge of the electrons balances the positive charge of the protons, atoms are neutral.

14. Jons Berzelius… introduced a system of abbreviation for the elements, which is still in use today. The symbol was determined by using the first letter of the element’s name or Latin name and capitalizing it and in most cases added another letter, which remained lower case.

15. The atomic symbol is where you capitalize the first letter and if there are any other letters in the symbol they are lower case. Examples: H for Hydrogen O for Oxygen Ca for Calcium Au for Gold

16. Chemical formulas show what elements and how many atoms of that element have combined to make a compound/chemical!

17. Can you tell what elements it took to make the following chemicals/compounds? Hydrochloric Acid: HCl Sodium Chloride: NaCl Cream of Tartar: KHC 4 H 4 O 6 Battery Acid: H 2 SO 4 Starch: C 6 H 10 O 5 Aspirin: C 9 H 8 O 4 Water: H2O Carbon Dioxide: CO2 Baking Soda: NaHCO3 Sugar: C12H22O11 Ammonia: NH3 Rubbing alcohol: C3H7OH

18. Atom vs. Molecules Element is a pure substance that cannot be broken down any further. It is in its simplest form! Each element is represented by an atom. Molecules are particles made up of two or more atoms bonded together that make up substances.

19. Compound vs. Mixture Compound is a substance that is made up of two or more elements chemically bonded together. Mixture is a substance that is made up of two or more elements, but the elements are not chemically bonded together.

20. Two types of mixtures!!! Homogeneous and Heterogeneous Let’s use the prefixes to help us remember which one is which!!! Remember, Prefixes bring with them a meaning to whatever we attach them to Homo vs. Hetero Homo means same Hetero means different

21. Homogeneous- a mixture in which substances are evenly distributed throughout the mixture. It all looks the same!!! Example, Milkshake Heterogeneous Mixture- a mixture in which substances are unevenly distributed throughout the mixture. You can see the different parts!!! Example, Fruit Salad

22. Dmitri Mendeleev… arranged the elements into a systematic chart or table called the Periodic Table of Elements. Today’s periodic table of elements based on Mendeleev’s version groups the elements by similar properties. It gives the symbol, the atomic number, and the atomic mass of each element.

23. 1 H Hydrogen 1.0079 Atomic Number-tells you the amount of protons and electrons. Atomic Symbol Full Name Atomic Mass An example of how an atom is represented on the Periodic Table of Elements.

24. How do you know how many protons, electrons, and neutrons each atom has? The atomic # tells you how many protons and electrons there are in each atom. You need a formula to calculate the amount of neutrons. The formula is: Atomic mass(large #) minus the Atomic #(smaller #) equals the amount of neutrons. or AM – A# = neutrons

25. Practice finding the amount of Protons, Electrons, and Neutrons: 1.Aluminum 2.Oxygen

26. Practice continued 3. Mercury 4. Hydrogen

27. The Periodic Table of Elements Each box on the table represent an atom. Start seeing each element as a different atom. The atoms are arranged periodically based on their properties/characteristics. It works out that the atoms are in order of increasing atomic number (protons/electrons) as you move from left to right. The boxes are arranged into a grid of periods (Horizontal rows) and groups (Vertical columns)

28. Two different numbering systems! One of the numbering systems: –Numbers the groups(columns) 1-18! The other numbering system: –Divides the table of elements into two categories: Main Group Elements- the first two groups(columns) and last six groups(columns). We notate the group number with the letter “A”. (Ex., 2A) Transition Metals-the ten groups(columns) in the center. We notate the groups number with the letter “B”. (Ex., 3B)

29. List the numbers as they would appear at the top of each column on the P.T.o.E.: 1_ 2_ ___ ___ ___ ___ ___ __ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ _1a_ 2a_ ___ ___ ___ ___ ___ __ ___ ___ ___ ___ ___ ___ ___ ___ ___ ___ Using Period #’s and Group #’s as coordinates to locate elements/atoms: 1. P2 G17: 2. P4 G4a: 3. P3 G6a: 4. P6 G12:

30. Groups are sometimes called families! Alkali metals (Group 1)-highly reactive & do not occur freely in nature. Alkaline Metals (Group 2)-highly reactive & found on earth. Rare Earth Elements(Inner transition metals)- synthetic(man-made) Hologens (Group 17)-non-metals that require only one more valence electron to be stable. Noble Gases (Group 18)-they do not combine easily if at all with other atoms/elements.

31. Let’s talk organization! The elements are divided into 3 categories: Metals, Metalloids, and Nonmetals. We use the “Zig-Zag” line as a reference.

32. The metals are to the left of the “Zig-Zag” line except: Hydrogen-it’s a nonmetal The metalloids are on the “Zig-Zag” line. except: Aluminum, it’s all metal! The nonmetals are to the right of the “Zig-Zag line. except: Hydrogen-even though it is located to the left it is still a nonmetal

33. Memorizing the states of each atom at room temperature helps use the periodic table as a tool! There are 11 gases and 2 liquids at room temperature: hydrogen- Helium- Nitrogen Oxygen Fluorine Chlorine Neon Xenon Argon Krypton Radon Gases Bromine Mercury Liquids

34. Each atom has energy levels/orbitals that can only hold a certain amount of electrons. Electrons in orbitals farthest away from the nucleus have higher amounts of energy than those found in orbitals closer to the nucleus. Holding Atoms in a Compound Together!

35. The electrons in the most outer energy level/orbital have the most energy and are called valence electrons. The valence electrons are the electrons involved in forming chemical bonds. Chemical bonds are the attraction between atoms in a compound.

36. How many Electrons are located in the most outer energy level? These are the valence electrons which are used to bond with!!

37. It’s easy…..just look at the periodic table!! The group # tells you the number of valence electrons: –Group 1(1a)= 1 valence electron –Group 2(2a)= 2 valence electrons –Group 13(3a)= 3 valence electrons –Group 14(4a)= 4 valence electrons Helium, which only has 2 valence electrons, is the exception in group 18(8a). How do you know how many Valence Electrons each atom has?

38. Noble Gases have 8 valence electrons, which makes them the most stable!  Remember: Helium only needs 2 to be considered stable! The octet rule: an atom will form a chemical bond with another atom if the bonding will cause both atoms to have 8 valence electrons.  Remember: Hydrogen & Helium only need 2 to be considered stable! Dot Structures: a tool used to help illustrate how atoms conform to the octet rule in a compound. Plus, they’re fun to make

39. Ionic Bonding  occurs when a metal transfers one or more electrons to a nonmetal in an effort to attain a stable octet of electrons.  One of the ions will be a positively charged ion and the other will be a negatively charged ion. –Example: Cs + At = – –Example: Na + S = – –Example: Ga + Br =

40. Example: C + O = Example: H + O = Example: H + H = Covalent Bonding- occurs when two or more nonmetals share electrons, attempting to attain a stable octet of electrons at least part of the time.

41. A combination of more than one nonmetal atoms with at least one metal atom. This is three or more elements! It is a Polyatomic Ionic Bond if…  There are 3 or more elements and at least one of the elements is a metal!!!!! Polyatomic Ionic Bonding

42. Identify the following as Ionic, Covalent, or a Polyatomic ionic bond: 7.Na 2 CO 3 8.CH 4 9.SO 3 10.LiBr 11.MgO 12.NH 4 Cl 1. CaCl 2 2.CO 2 3.H 2 O 4.BaSO 4 5.K 2 O 6.NaF

43. Things to remember: That chemistry is study of matter, including its properties, composition, and the changes it undergoes. That matter is anything that has mass and volume (takes up space)

44. What is a Property? A property is a quality specific to a substance that helps us to classify or identify the substance. It is a description of matter!

45. What is the difference between a Property and a Change? A property is the description/characteristic of matter and/or ability to change. A Change is the actual change or reaction that occurs.

46. Physical Property/Change Physical Property- a characteristic of matter that can be observed and sometimes changed without producing a new kind of matter. Color, size, texture, and shape are examples of physical properties.

47. More Examples of Physical Properties Density- how tightly packed matter is in a given amount of space (D= m/v) Malleability- the ability to be hammered into a shape. Viscosity- a fluids resistance to flow. Ductility- the ability to be pulled into thin wires. Solubility-the ability to dissolve.

48. Chemical Property A chemical property is a description of how a certain kind of matter reacts. When matter reacts one of two things happen: The matter combines with another form of matter to produce a new kind of matter? Or Does the matter break apart to produce a new kind of matter? Which one would be decomposition and which one would be composition?

49. Composition Reaction A composition reaction involves combining two forms of matter to produce a new kind of matter. For example, when sodium is combined with chloride…salt is formed.

50. An Example of a Composition Reaction: The iron metal of nails combined with oxygen forms a reddish-brownish solid called rust. Rust is a new kind of matter with its own set of physical and chemical properties.

51. Decomposition A Decomposition reaction involves combining one type of matter with something else (matter or energy). The matter breaks down and forms a new kind of matter. Think about wood burning.

52. There are four basic Chemical Properties/Changes: The ability to react with acid The ability to react with oxygen(burning and rusting) The ability to react with electricity The ability to react with another substance

54. Example of a Chemical Property/Change When Oxygen( a kind of matter) combines with aluminum (also a kind of matter) it has the ability to form a coating. This coating is a new kind of matter with different physical and chemical properties.

55. Copy the following and write down whether it is physical or chemical next to it:

56. Physical or Chemical? Ductility- Flammability- Reacts with Acid to form H2O- Solubility- Sour Taste- Viscosity- Odor- Reacts with water to form a gas-

57. Phases of Matter The phases of Matter are a physical property of matter. Think about water for example. Plasma Solid Liquid Gas There are four different phases of matter:

58. Plasma Plasma is a phase of matter that is similar to a gas. Unlike gas, Plasma is produced by burning gases at very high temperatures, as in the sun and other stars. It may also be produced if the matter is exposed to a significant electrical current.

59. Solid A solid has definite shape and definite volume. Under regular circumstances, the shape and volume of solids do not change. Molecules vibrate in place

60. Liquid A liquid has a definite volume, but not a definite shape. Liquids take the shape of the container they are in, but the volume remains the same. Molecules have a rapid, random motion.

61. Gas A Gas does not have a definite shape or a definite volume. Like liquids the gas takes the shape of its container. (Remember the balloon and air?) Unlike Liquids the volume does not necessarily stay the same. Molecules have very rapid, random motion.

62. There are several words that indicate a possible change in phase and all would result in physical changes. Use the following list as key words for physical properties and changes!!! *melting- *freezing- *evaporating- *sublimation- *boiling- *vaporization- *condensation-

63. Two Types of Solids: An Amorphous Solid - the molecules are not arranged in a fixed regular pattern; they are arranged in a random pattern. Solids that have a random pattern are called amorphous. A Crystalline solid - the molecules are arranged in a fixed, regular pattern Solids that have such a repeating pattern are called crystals.

64. Physical vs. Chemical The following are key words that represent either physical or chemical changes. The letter “p” identifies a physical change key word and the letter “c” identifies a chemical change key word: 1.cuts- 2.boils- 3.burns- 4.corrodes- 5.smash- 6.rusts-

65. 7.evaporates- 8.reacts- 9.hammering- 10.viscosity- 11.spoiling- 12.folds- 13.decomposes- 14.paint- 15.mixing- 16.combining-

66. 17. dissolve- 18. luster- 19. bleach- 20. density- 21- bonds with- 22. malleability- 23. ductility- 24. mixture- 25. compound-

67. Are we finished? You bet we are!!!!!