PSYC 2000 Chapter : Chap 1 F11
Chapter 1
Intro/Sig Figs
0.00008 (How many sigs)
2.334 x 3.0 = ?
(8.00 m)(100 cm/m)(1 in./2.54 cm) = ?
Types of Properties
• Physical Properties…
– Can be observed without changing a
substance into another substance.
Ex: Boiling point, density, mass, volume, etc.
• Chemical Properties…
– Can only be observed when a substance is
changed into another substance.
Ex: Flammability, corrosiveness, reactivity with
acid, etc.
Types of Changes
• Physical Changes
– These are changes in matter that do not
change the composition of a substance.
Ex: Changes of state (s, l, g), temperature, volume,
etc.
• Chemical Changes
– Chemical changes result in new substances.
Ex: Combustion, oxidation, decomposition, etc.
CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g)
The Process of Science and Discovery
• The word science is derived from a Latin verb
meaning “to know.” Science is a Creative (esp.
chemistry!) cycle of discovery and analysis
How do we handle such data? Glad you asked…
Precision – how closely the
measurements agree with one another.
Document Summary
Can be observed without changing a substance into another substance. Ex: boiling point, density, mass, volume, etc: chemical properties . Can only be observed when a substance is changed into another substance. These are changes in matter that do not change the composition of a substance. Ex: changes of state (s, l, g), temperature, volume, etc: chemical changes. Ch4 (g) + 2 o2 (g) co2 (g) + 2 h2o (g) The process of science and discovery: the word science is derived from a latin verb meaning to know. science is a creative (esp. chemistry!) cycle of discovery and analysis. Precision how closely the measurements agree with one another. Accuracy how close the measurement is to the true value. All the digits of the measured quantity, including the uncertain one (last number) are called significant figures. Example: 3. 45 (3 sig figs), 4. 3789999 (8 sig figs) What is tricky is how we treat zeros in a measured quantity.
