Ch 3 Student Notes

Ch 3 Student Notes - 1 Ch 3 Atomic Structure and the...

Info iconThis preview shows pages 1–10. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Ch 3 Atomic Structure and the Periodic Table Figure 3.1 size relationship is not to scale, ratio of average diameters atom/nucleus = 10 5
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Atoms are very small and spherical. Radii Range 0.9 x 10 -10 to 2.4 x 10 -10 m 90 – 240 pm Recall Figure 1.12 Atomic Mass example: 1 H atom = 1.673 x 10 -24 g 1atomic mass unit (amu) = 1.6605 x 10 -24 g For H: 1.673 x 10 -24 g x 1 amu . 1.6605 x 10 -24 g = 1.008 amu
Background image of page 2
3 Ch 3.1 Internal Structure of an Atom Subatomic particles An atom is characterized by the number of protons ( p ) that it contains. A proton has a positive electrical charge. p charge = 1.60 x 10 -19 coulombs = +1 relative charge p mass = 1.6726 x 10 -24 g = ______ amu A neutron ( n ) has no charge associated with it. n mass = 1.6750 x 10 -24 g = ______ amu An electron ( e ) has a negative electrical charge. e charge = - 1.60 x 10 -19 coulombs = -1 relative charge e mass = 9.109 x 10 -28 = _________ amu mass of p ~ mass of n >>> mass of e - mass of e - is often ignored
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Ch 3.2 Atomic Number and Mass Number Atomic number = Z = # of protons (unique physical property of each element) Mass number = A = # of protons + # of neutrons # of neutrons = ___________ For a neutral atom, net electrical charge = zero # of electrons = # of protons = _____ A E complete chemical symbol notation Z
Background image of page 4
5 A 23 E Na Z 11 # p = Z = ____ # n = A Z = ________ = ____ # e - = # p = ____
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Ch 3.3 Isotopes and Atomic Masses Isotopes are atoms of an element that have the same number of protons and electrons but different numbers of neutrons. 12 13 14 C C C 6 6 6 isotopes have nearly identical chemical properties most elements have at least two isotopes
Background image of page 6
7 Table 3.2 Elements with Z = 1 through 12 The atomic mass of an element is the calculated weighted average mass for the isotopes.
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
8 Chem 101 Grading Scheme Quizzes 180 points 180/1000 = 0.18 Labs 160 points 160/1000 = 0.16 Exams 660 points 660/1000 = 0.66 1000 1.00 Sample calculation of weighted average Quizzes 85 % x 0.18 = 15.3 % Labs 95 % x 0.16 = 15.2 % Exams 55 % x 0.66 = 36.3 % Average ___% ____ % Weighted Average
Background image of page 8
35 37 Cl Cl 17 17 34.96885 amu 36.96590 amu 75.77 % 24.23 % natural abundance atomic mass of Cl = weighted average mass for the isotopes 34.96885 x 75.77/100 = 25.60 36.96590 x 24.23/100 = 8.957 35.46 amu 63 65 Cu Cu 29 29 62.9298 amu 64.9278 amu Atomic weight Cu = 63.546 amu Which isotope is the more abundant? Answer:
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 10
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 06/03/2011 for the course CHM 123 taught by Professor Woodward during the Fall '08 term at Ohio State.

Page1 / 36

Ch 3 Student Notes - 1 Ch 3 Atomic Structure and the...

This preview shows document pages 1 - 10. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online