Chapter 3
Stoichiometry
Atomic Mass
Micro World
atoms & molecules
Macro World
grams
Atomic mass is the mass of an atom in atomic mass
units (amu).
By definition:
1 atom 12C weighs 12 amu
On this scale
1H
= 1.008 amu
16O
= 16.00 amu
Average Atomic Mass
Ave
Study Guide for Chapter 2:
Names and symbols of highlighted elements in slide #2 (chapter 2).
Daltons atomic theory
Three theories of matter
Atom: subatomic particles (protons, neutrons, electrons); isotopes.
Periodic table: arranged according to increasi
Study Guide for Chapter 3:
Atomic and molar (molecular) masses
Mole: you should know Avogadros number (6.022 x 1023 atoms, molecules, particles); molar
mass of any substance in grams (g/mol) is numerically equal to its formula mass in amu.
Percent composi
Composition (f g )(x) = f (g (x)
A composition function, f (g (x), is a function of function.
Notation: f g (f g )(x) = f (g (x).
Example
Given that f (x) = sin x, g (x) =
f g = f (g ) = sin(g ) = sin ( 1 + x).
g f = g (f ) = 1 + f = 1 + sin x.
f f = f (f