1 / 25

Chapter Three

0. Chapter Three. Atoms and the Periodic Table. 0. Atomic Theory. All matter is composed of atoms Atoms of each element are unique Atoms are composed of subatomic particles (protons, neutrons and electrons) Atoms combine to form compounds in definite proportions

Olivia
Download Presentation

Chapter Three

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 0 Chapter Three Atoms and the Periodic Table

  2. 0 Atomic Theory • All matter is composed of atoms • Atoms of each element are unique • Atoms are composed of subatomic particles (protons, neutrons and electrons) • Atoms combine to form compounds in definite proportions • Chemical compounds undergo changes in composition and identity in reactions, atoms remain unchanged • Atoms change identities in nuclear reactions

  3. 0 Nature of the Atom • Atoms are small 10-11 meters • 1 Angstrom = 10-10 meters

  4. 0 Subatomic Particles

  5. 0 Atomic Number (Z) • number of protons in nucleus • unique for each element • elements placed in periodic table by increasing number of protons sodium has 11 protons 11Na carbon has 6 protons 6C

  6. 0 Elements are neutral Number of positive protons = Number of negative electrons

  7. 0 Mass Number (A) Number of particles in the nucleus Protons + Neutrons = Mass Number Protons + Neutrons = Nucleons

  8. 0 Isotopes • Elements may have several different isotopes • Same number of protons, different number of neutrons

  9. 0 Atomic Weight The average mass number of all the naturally occurring isotopes according to relative abundance. Lithium is 6.941. There is more lithium-7 than lithium-6

  10. 0 Electrons in Atoms • Energy is quantized vs continuous • Quantize = step function • Continuous = all values are present • Similar to digital vs analog

  11. 0 Shells, Subshells and Orbitals • Shells • n = principle quantum number • Same as period on periodic table • Subshells • In each shell s > p > d > f • Orbitals • 2 electrons per orbital

  12. 0 Orbitals • s subshell – 1 orbital – 2 electrons • p subshell – 3 orbitals – 6 electrons • d subshell – 5 orbitals – 10 electrons • f subshell – 7 orbitals – 14 electrons

  13. 0 Number of Electrons in Shells 2n2 n is the number of the row in the periodic table

  14. 0 Aufbau – order of filling • 1s2 • 2s22p6 • 3s23p63d10 • 4s24p64d104f14 • 5s25p65d105f14(5g18) • 6s26p66d106f14(6g18)(6h22) • 7s27p67d106f14(6g18)(6h22)(7i26)

  15. 0 Increasing Energy • 1s22s22p63s23p64s23d104p6 • Carbon 6 electrons • 1s22s22p2 • Sodium 11 electrons • 1s22s22p63s1

  16. 0 • Aluminum – 13 electrons • 1s22s22p63s23p1 • Calcium – 20 electrons • 1s22s22p63s23p64s2 • Iron – 26 electrons • 1s22s22p63s23p64s23d6 • Bromine – 35 electrons • 1s22s22p63s23p64s23d104p5

  17. 0 Using the Periodic Table • Lithium – 3 electrons • 1s22s1 • Sodium – 11 electrons • 1s22s22p63s1 • Potassium – 19 electrons • 1s22s22p63s23p64s1 • All end in “ns1” configuration

  18. Fluorine – 9 electrons • 1s22s22p5 • Chlorine – 17 electrons • 1s22s22p63s23p5 • Iodine – 53 electrons • 1s22s22p63s23p64s23d104p65s24d105p5 • All end in “ns2np5” configuration

  19. The Periodic Table • Classification by Properties • Arranged by increasing atomic number • Rows=periods, columns=groups (families) • Main Group – Representative • IA, IIA, IIIA, IVA, VA, VIA, VIIA, VIIIA • Transition Metals • 10 columns in middle of table • Inner-transition Metals • 14 columns at bottom of table

  20. Elements in same column have similar properties • Cu, Ag and Au – shiny metals, malleable, conduct electricity

  21. Names of Families • Alkali Metals (IA) Na and K • Alkaline Earth Metals (IIA) Mg and Ca • Halogens (VIIA) F, Cl, Br and I • Noble Gases (Inert Gases) (VIIIA) He, Ne, Ar, Kr and Xe

  22. Neighboring Groups • Metals • Non-metals • Metalloids (Semiconductors)

  23. Dot Structures for Atoms • Valence electrons for representative elements = group number • Octet rule

  24. Noble Gas Shorthand • [He] = 1s2 Li = 1s22s1 or [He]2s1 • [Ne] = 1s22s22p6 Na = [Ne]3s1 Mg = [Ne]3s2 • [Xe] = 1s22s22p63s23p64s23d104p65s24d105p6 Ba = [Xe]6s2

  25. Location on Periodic Table shows location of last electron in configuration • Cs = 6s1 • Sr = 5s2

More Related