Chemistry: Chapter 1

Hypothesis

a proposed explanation for pattern observed in the natural world - Must be stated in a way that can be tested by experiments - A first "educated guess" to explain a set of observations

Antione Lavoisier (1743-1794) Experiments

- Phosphorus Burning Experiment - Mercury Burning experiment

Law

Science is governed by as yet irrefutable laws - a statement that describes a pattern of regularity in nature - an explicit statement of fact

Hypothesis vs Theory

Theory: Tested repeatedly and not disproven Hypothesis: Hypotheses are repeatedly tested (with planned experiments) by the scientific community -> CAN become a theory

Which of the following is a possible explanation for a set of observations? a. A hypothesis b. A law c. An experiment d. A measurement

a. a hypothesis

Which of the following is another name for a scientific test? a. an experiment b. a discussion c. a natural law d. a theory e. a hypothesis

a. an experiment

Chemistry is a(n) _______ science. a. experimental b. performing c. trivial d. biological e. unimportant

a. experimental

Quantitative Observation

are made with instruments such as rulers, balances, graduated cylinders, beakers, and thermometers. These results ARE measurable and involve numbers.

A chemical theory that has been known for a long time becomes a law. a. True b. False

b. False

Chlorofluorocarbons (CFCs) are a type of industrial chemical. It was noted in the 1980s that as the production of CFCs increased, damage to the earth's ozone layer increased. With this information, classify the statement, "CFCs damage the ozone layer." a. law b. hypothesis c. observation d. experiment

b. hypothesis

A quantitative observation is known as a. an experiment b. a theory c. a measurement d. a hypothesis

c. a measurement

Which of the following is a probable explanation for a set of observations or a set of tested hypotheses? a. A measurement b. An experiment c. A theory d. An observation

c. a theory

What did Lavoisier use to test the phlogiston theory? a. Cobalt b. Aluminum c. Phosphorous d. Wood

c. phosphorous

A quantitative observation: a. does not contain a number b. must be obtained through experimentation c. always makes a comparison d. contains a number and a unit e. None of these choices are correct....

d. contains a number and a unit

"What goes up must come down" is an example of a scientific a. model b. theory c. hypothesis d. law

d. law

Qualitative Observation

deals with data that can be observed with our senses: sight, smell, touch, taste, and hearing. they DO NOT involve measurements or numbers.

Molecules

the smallest unit particle of a pure substance that can exist independently and possess the identity of the substance.

Scientific Method

the typically cyclical procedure used to create knowledge about the natural world, characterized by observation and measurement, proposing a hypothesis, testing and revising the hypothesis, and combining a group of related hypotheses into a theory.

Observation

Divides in to two types: qualitative vs quantitative observation

Theory or Scientific Model

a related set of hypotheses that explain a broad group of related phenomena