Chapter 1: Chemistry: The Study of Change

Chemistry: A Science for the 21st Century • Health and Medicine • pharmaceuticals • gene therapy • Energy• nuclear fission/fusion • computer chips • genetic engineering • Food and Agriculture • fertilizers • pesticides • biotechnology

The Scientific Method • • Systematic approach to research (to figuring out

things) • • Science organized body of knowledge based on

experiment and observation • Experiment → Observation → Law →

Theory • Law: a concise verbal or mathematical study of

the relationship between phenomena that are always the same under the same conditions.

• Theory: unifying principle that explains a body of facts and the laws that are based on those facts.

Classification of Matter • • Matter - anything that occupies space and has mass • • all matter is made up of chemicals • • Mixture: combination of 2 or more substances in which

the substances retain distinct identities (air, milk, cement, tea, coffee)

• • Homogeneous mixture: same composition throughout (sugar in water, tea)

• • Heterogeneous mixture: non-uniform composition (sand + iron filings)

• • Elements: substance that cannot be separated into simpler elements by chemical means

• • Compounds: substance composed of atoms of 2 or more elements chemically united in fixed proportions

LEARN First 36 Elements in the PERIODIC TABLE

Physical and Chemical Properties of Matter • • Physical Property: can be measured and

observed without changing the composition or identity of a substance.

• • Chemical Property: requires a chemical change in

order to be observed.

Measurement • e.g., k = kilo 1 km = 1000 m • n = nano 1 nm = 10-9 m • KNOW at least the following Metric-English

Conversions • length: 1 inch = 2.54 cm or 1 m = 39.37 inches • mass: 1 kg = 2.205 lb or 1 lb = 454 g • volume: 1 gal = 3.786 L

Temperature Scales • Fahrenheit °F °F = (9/5) °C + 32 • Celsius °C °C = (5/9) (°F - 32)

• Kelvin K °K = °C + 273.15

Home work

1-Give me the meaning of the following term:Law- Theory- Matter- Mixture- Homogeneous mixture- Heterogeneous mixture- Elements- Compounds

2-Make the following conversions :a) 9 in to m (1 in = 2.54 cm)b) 77°F to Kelvinc) 7.92 lb/gal to g/mL (1 lb = 453.6 g, 1 gal = 3.785 L)