Basic Building Materials

1. Basic Building Materials

2. A New Language • ELEMENTS: • Hydrogen, oxygen, chlorine, sodium, and iron are examples of elements. • Elements cannot be resolved into simpler substances by ordinary heat, light, electricity, or attack by other substances. • Elements can be broken down but it takes millions of times more energy than can be applied by ordinary means – it requires special equipment, such as a particle accelerator, or temperatures like those in the interior of the sun. • Elements are, therefore, defined as a substance that cannot be broken down into simpler substances by ordinary means.

3. Ninety elements are known to occur in nature, and 22 more have been made artificially. Out of this limited number of elements, all the millions of known substances are made. • In summary: • A form of matter that is a pure substance • Cannot be decomposed • Composed of atoms • Each atom in an element has the same number of protons (atomic #)

4. Atomic number Atomic mass Atomic number – number of protons in atoms Atomic mass – weighted average of all masses of isotopes of the element

5. Chemical Symbols • Abbreviating the names of the elements is often convenient. For each element, a symbol has been chosen that consists of one or two letters. • Chemical elements are assigned unique chemical symbols, based on the name of the element, but not necessarily in English.

6. Sodium has the chemical symbol “Na” after the Latin natrium. • Tungsten is “W” for wofram • Mercury is “Hg” for hydrargyrum • Potassium is “K” for kalium • Antimony is “Sb” for stibium

7. The first letter of a chemical symbol is always capitalized, and the subsequent letter, if any, is always in lower case (small letters). • Examples: • Fr = Francium F = Fluorine • Li = Lithium B = Boron • Fe = iron (ferrous) P = Phosophorus • Cu = copper (cuprous)

8. ELEMENTS: • Simplest form of matter that have a unique set of properties • Three classifications of elements • Metals, non-metals, metalloids • Classified because they have same physical & chemical properties

9. TYPES OF ELEMENTS: • MONOATOMIC elements: composed of one atom • DIATOMIC elements: composed of two of the same atom • H O F Br I N Cl • These elements will always occur as pairs – O2,, H2, N2

10. Use the Periodic table to color the monoatomic and diatomic elements in your packet

11. It’s Elemental • A chemical element, often called simply an element, is a substance that cannot be decomposed or transformed into other chemical substances by ordinary processes. All matter fundamentally consists of these elements and as of 2006, 116 unique elements have been discovered or artificially created.

12. Particle Diagrams • Elements and compounds can be represented using particle diagrams, which is a box in which colored balls are draw to represent atoms or molecules. • These diagrams can represent elements and compounds, as well as their molecular composition by the types of balls and how they are connected.

13. Particle Diagrams - Elements • The following are examples of two particle diagrams of elements: A monatomic element A diatomic element

14. Particle Diagrams -Compounds • Compounds have more than one element connected to one another

15. Particle Diagrams - Mixtures • Particle diagrams can represent pure substances or mixtures.

16. Solids • A solid has a fixed volume and fixed shape. • Atoms are in direct contact and there is very little movement except for atomic vibrations • There are two types of solids – Crystalline solids have a regular repeating three dimensional pattern of atoms or molecules – Amorphous solids do not have a regular repeating pattern of atoms or molecules

17. Liquids • A liquid has a fixed volume, takes the shape of its container, does not have a regular repeating pattern of atoms or molecules, the atoms or molecules are in constant motion, not all atoms are in direct contact and there may be a meniscus due to the intermolecular forces of attraction between the liquid and its container.

18. Gases • Gases expand to fill and take the shape of their container. • Gas molecules are not in direct contact, are in constant motion, have elastic collisions and most of the volume is empty space.

19. Particle Diagrams of Solid, Liquid & Gas Gas Solid Liquid

20. Complete the Periodic Table in your packet. Choose a color for each phase and color the table accordingly

21. The Periodic Table Visit www.worldofteaching.com For 100’s of free powerpoints

22. Why is the Periodic Table important to me? • The periodic table is the most useful tool to a chemist. • You get to use it on every test. • It organizes lots of information about all the known elements.

23. Pre-Periodic Table Chemistry … • …was a mess!!! • No organization of elements. • Imagine going to a grocery store with no organization!! • Difficult to find information. • Chemistry didn’t make sense.

24. HOW HIS WORKED… Put elements in rows by increasing atomic weight. Put elements in columns by the way they reacted. SOME PROBLEMS… He left blank spaces for what he said were undiscovered elements. (Turned out he was right!) He broke the pattern of increasing atomic weight to keep similar reacting elements together. Dmitri Mendeleev: Father of the Table

25. The Current Periodic Table • Mendeleev wasn’t too far off. • Now the elements are put in rows by increasing ATOMIC NUMBER!! • The horizontal rows are called periods and are labeled from 1 to 7. • The vertical columns are called groups are labeled from 1 to 18.

26. Groups…Here’s Where the Periodic Table Gets Useful!! • Elements in the same group have similar chemical and physical properties!! • (Mendeleev did that on purpose.) • Why?? • They have the same number of valence electrons. • They will form the same kinds of ions.

27. Modern Periodic Law • When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.

28. Families on the Periodic Table • Columns are also grouped into families. • Families may be one column, or several columns put together. • Families have names rather than numbers. (Just like your family has a common last name.)

29. Hydrogen • Hydrogen belongs to a family of its own. • Hydrogen is a diatomic, reactive gas. • Hydrogen was involved in the explosion of the Hindenberg. • Hydrogen is promising as an alternative fuel source for automobiles

30. Alkali Metals • 1st column on the periodic table (Group 1) not including hydrogen. • Very reactive metals, always combined with something else in nature (like in salt). • Soft enough to cut with a butter knife

31. Alkaline Earth Metals • Second column on the periodic table. (Group 2) • Reactive metals that are always combined with nonmetals in nature. • Several of these elements are important mineral nutrients (such as Mg and Ca)

32. Transition Metals • Elements in groups 3-12 • Less reactive harder metals • Includes metals used in jewelry and construction. • Metals used “as metal.”

33. Boron Family • Elements in group 13 • Aluminum metal was once rare and expensive, not a “disposable metal.”

34. Carbon Family • Elements in group 14 • Contains elements important to life and computers. • Carbon is the basis for an entire branch of chemistry. • Silicon and Germanium are important semiconductors.

35. Nitrogen Family • Elements in group 15 • Nitrogen makes up over ¾ of the atmosphere. • Nitrogen and phosphorus are both important in living things. • Most of the world’s nitrogen is not available to living things. • The red stuff on the tip of matches is phosphorus.

36. Oxygen Family or Chalcogens • Elements in group 16 • Oxygen is necessary for respiration. • Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)

37. Halogens • Elements in group 17 • Very reactive, volatile, diatomic, nonmetals • Always found combined with other element in nature . • Used as disinfectants and to strengthen teeth.

38. The Noble Gases

39. The Noble Gases • Elements in group 18 • VERY nonreactive, monatomic gases • Used in lighted “neon” signs • Used in blimps to fix the Hindenberg problem. • Have a full valence shell.

40. Complete the Periodic Table in your packet by coloring the different Families

41. Periods on the Periodic Table • Horizontal rows of the Periodic Table are called Periods • There are seven periods

42. Color the Periods on the Periodic Table in your packet

43. Metals • Good conductors of heat & electric current • Have high luster or sheen when freshly cleaned • Reflect light • Solid at room temperature (except mercury) • Ductile • Malleable

44. Nonmetals • Most are gases at room temperature eg. oxygen & nitrogen • Poor conductors • A few solids such as sulfur & phosphorus • Bromine is a dark-red liquid • Tend to be brittle (shatter if hit with a hammer)

45. Metalloids • Properties of both metals & nonmetals depending on the conditions • Eg. Pure silicon is a poor conductor. If a small amount of boron is mixed with silicon, the mixture is a good conductor

46. Complete your Periodic Table in your Packet showing metals, nonmetals, and metalloids