2.1 Scientific Method

All of the following are steps in the scientific method except

• observing and recording data

• forming a hypothesis

• discarding data inconsistent with the hypothesis

• developing a model based on experimental results

Which of the following observations is quantitative?

• The liquid turns blue litmus paper red.

• The liquid boils at 100 degrees C

• The liquid taste bitter.

• The liquid is cloudy.

Which of the following observations is qualitative?

• A chemical reaction was complete in 2.3 seconds.

• The solid had a mass 23.4 grams.

• The pH of a liquid was 5.

• Salt crystals formed as the liquid evaporated.

A statement that can be tested experimentally is a

• variable

• model

• generalization

• hypothesis

A theory is best described as a

• series of experimental observations.

• generalization that explains a body of known facts or phenomena.

• scientifically proven fact.

• testable statement.

A plausible explanation of a body of observed natural phenomena is a scientific

• control

• experiment

• law

• theory

Quantitative observations are recorded in the form of

• numerical data

• detailed descriptions

• precise predictions

• step-by-step procedures

Which of these statements about the scientific method is not true?

• All experiments must follow the same step-by-step procedure.

• Experiments may be repeated several times.

• Some unexpected results can be beneficial.

• Experimental results may or may not support the hypothesis.

Ten plants are grown in equal amounts of sunlight with equal amounts of water and varying amounts of fertilizer. Sunlight, water, and fertilizer are

• controls

• experiments

• systems

• variables

An experiment was designed to measure the effect of sulfur dioxide emissions from a power plant of the pH of rain falling downwind of the plant. In this experiment, the average pH of rainwater upwind from the plant would be considered

• a model

• a variable

• the hypothesis

• the control