Unit 2 – Chapters 2, 8, & 9

1. Unit 2 – Chapters 2, 8, & 9 The Components of Matter

2. Definitions for Components of Matter ________________ - the simplest type of substance with unique physical and chemical properties. An element consists of only one type of atom. It cannot be broken down into any simpler substances by physical or chemical means. __________________- a structure that consists of two or more atoms that are chemically bound together and thus behaves as an independent unit.

3. Definitions for Components of Matter __________________ - a substance composed of two or more elements which are chemically combined. ________________ - a group of two or more elements and/or compounds that are physically intermingled.

5. __________________ (1766-1844), an English schoolteacher and chemist, studied the results of experiments by Lavoisier, Proust, and many other scientists.

6. Dalton’s Atomic Theory • Dalton proposed his atomic theory of matter in 1803. • Although his theory has been modified slightly to accommodate new discoveries, Dalton’s theory was so insightful that it has remained essentially intact up to the present time.

7. Dalton’s Atomic Theory The Postulates 1. All matter consists of ______________________. 2. Atoms of one element ___________________ be converted into atoms of another element. 3. Atoms of an element are _____________________ in mass and other properties and are _______________________ from atoms of any other element. 4. ______________________________ result from the chemical combination of a specific ratio of atoms of different elements.

8. Structure of the Atom • J.J. (John Joseph) Thomson, physicist • 1890-1900 • Showed that the atoms of any element can be made to emit tiny negative particles - called _______________________. • Thompson knew that the entire atom was not negatively charged so he concluded that the atom must also contain positive particles that balance the negative charge, giving the atom a ___________________________________.

9. Ernest Rutherford • 1911 • Learned physics in J.J. Thomson’s laboratory in the late 1890s. • Main area of interest was the _____________________________ - positively charged particles with a mass approximately 7500 times that of an electron.

10. Ernest Rutherford • By 1919, Rutherford concluded that the nucleus of an atom contained what he called ______________________(has the same magnitude of charge as the electron, but its charge is positive) • Protons have a _________ charge and the electron a charge of ______________. • 1932, he and a coworker (James Chadwick) were able to show that most nuclei also contain a neutral particle that they named the _________________ (which has no charge)

11. Modern Concept of Atomic Structure • The simplest view of the atom is that it consists of a tiny nucleus that is about 10-13 cm in diameter. • Electrons move about the nucleus at an average distance of about 10-8 cm from it. • Nucleus contains ___________________, which have a positive charge equal in magnitude to the electron’s negative charge, and ________________________, which have almost the same mass as a proton but no charge.

13. Modern Concept of Atomic Structure • Mass and charge of the electron (e-), proton (p+), and neutron (N)

14. Distinguishing Between Atoms • Protons and electrons are _______________ in an atom of an element (neutral charge). • The ________________________ of an element is the number of ______________ in the nucleus of an atom of that element. (If the p+ and e- are the same, then the atomic number will also identify the number of e-)

15. Distinguishing Between Atoms • The sum of the number of neutrons and the number of protons in a given nucleus is called the atom’s ____________________________. protons + neutrons = mass number • _____________________ • atoms with the same number of protons but different numbers of neutrons. • Elements on the periodic table are the most common isotopes of those substances.

16. Distinguishing Between Atoms • Isotopes • Because they have different numbers of _________________________, their mass numbers will be different. • Neon - 20 • Neon - 21 • Neon - 22 • All of these are isotopes of neon.

17. Distinguishing Between Atoms • Isotopes • 3 known isotopes of hydrogen • hydrogen - 1 [hydrogen] • hydrogen - 2 [deuterium] • hydrogen - 3 [tritium]

18. Isotopic Symbols • X = the symbol of the element • A = the mass number • Z = the atomic number A ZX 3 1 H Tritium 1 1 H Hydrogen 2 1 H Deuterium

19. Atomic Masses • Because atoms are so tiny, the normal units of mass - the gram and the kilogram - are much too large to be convenient. • Mass of a single carbon atom is 1.00 x 10-23 grams. • When describing the mass of an atom, scientists have defined a much smaller unit of mass called the __________________________.

20. Atomic Masses • In terms of grams: • 1 amu = atomic weight of a substance expressed in grams • 1 carbon atom = 12.01 amu = 12.01 grams • 1 aluminum atom = 26.98 amu = 26.98 grams

21. Periodic Table of Elements

22. Periodic Table of Elements • Shows all the known elements and gives a lot of information about each element. • Invaluable in chemistry!

23. Development of Periodic Table • Elements in the same group generally have similar ________________________________. • Properties are not identical, however.

24. Development of Periodic Table Dmitri Mendeleev and Lothar Meyer independently came to the same conclusion about how elements should be grouped.

25. Development of Periodic Table Mendeleev, for instance, predicted the discovery of germanium as an element with an atomic weight between that of zinc and arsenic, but with chemical properties similar to those of silicon.

26. Dmitri Mendeleev • Organized the elements according to their increasing __________________________. • Then he grouped them into columns and rows according to physical and chemical properties. • Row – __________________ • Column - __________________

29. Henry Moseley • Rearranged the elements according to their __________________________. • Arranging the elements in this manner provided for a better fit of chemical and physical properties and aligned those elements that were discovered after Mendeleev developed the original periodic table.

30. Parts of the Periodic Table of Elements • _____________________ – substances to the left of the dark line • _____________________ – substances to the right of the dark line • _____________________ – those elements that border the line

33. Properties of Metal, Nonmetals,and Metalloids

34. Metals versus Nonmetals Differences between metals and nonmetals tend to revolve around these properties.

35. Metals versus Nonmetals • Metals tend to form ____________. • Nonmetals tend to form _____________.

36. Metals Tend to be ______________, ______________, ______________, and good conductors of ______________ and ______________.

37. Metals • Compounds formed between metals and nonmetals tend to be ______________. • Metal oxides tend to be ______________.

38. Nonmetals • ______________, ______________substances that are ______________ conductors of heat and electricity. • Tend to gain ______________ in reactions with metals to acquire noble gas configuration.

39. Nonmetals • Substances containing only nonmetals are ______________ compounds. • Most nonmetal oxides are ______________.

40. Metalloids • Have some characteristics of ______________, some of ______________. • For instance, silicon looks shiny, but is brittle and fairly poor conductor.

41. Fireworks • Potassium – combustible element that helps oxidize firework mixtures • Lithium – adds red color • Sodium – gold and yellow colors • Magnesium – bright white color • Calcium – deepens the colors of the other elements in the fireworks • Strontium – red color and stablizes other elements • Barium – green color and stablizes other elements • Titanium – produces the spark • Iron – produces sparks • Copper – blue color • Zinc – smoke clouds • Aluminum – silver and white sparks and flames – sparklers • Carbon – black powder • Phosphorus – fuel • Sulfur – fuel • Antimony – glitter effects

42. Groups of the Periodic Table • Group 1 – Alkali metals • Group 2 – Alkaline Earth metals • Group 11 – Coinage metals • Group 17 – Halogens • Group 18 – Noble Gases

43. Electronic Structure

44. Electronic Structure • ______________ are vital in the determining the properties of elements. • Electrons are involved in bonding between ______________. • Electrons move around the nucleus in different ____________________________.

45. Energy Levels • There are ______________ energy levels – one for each corresponding row or period on the periodic table. • Within each energy level there are ______________.

46. Sublevels • Within each energy level there are a possibility of 4 sublevels – depending on which energy level you are dealing with.

47. Sublevels • The 4 different sublevels are: • _____ – holds a maximum of 2 electrons • _____ – holds a maximum of 6 electrons • _____ – holds a maximum of 10 electrons • _____ – holds a maximum of 14 electrons

48. Sublevels • Energy level 1 – only has an “s” sublevel • Energy level 2 – only has an “s” and “p” sublevel • Energy level 3 – only has an “s”, “p”, and “d” sublevel • Energy level 4 & 5 – have an “s”, “p”, “d”, and “f” sublevels • Energy level 6 – only has an “s”, “p”, and “d” sublevel • Energy level 7 – only has an “s” and “p” sublevel

49. Sublevels • Level 1 – maximum of ______________ • Level 2 – maximum of ______________ • Level 3 – maximum of ______________ • Level 4 & 5 – maximum of ___________ • Level 6 – maximum of ______________ • Level 7 – maximum of ______________

50. Orbitals • Within each sublevel, there are orbitals – locations where the electrons are actually located. • An orbital can hold 2 electrons only. • Sublevel “s” – _____orbital (total of 2 e-) • Sublevel “p” – _____orbitals (total of 6 e-) • Sublevel “d” – _____orbitals (total of 10 e-) • Sublevel “f” – _____orbitals (total of 14 e-)