Environmental Science A Chapter 1 Unit 1

Which of the following is an inference?

A cup with steam coming from it will be hot to the touch.

Which of the following statements describes a scientific law?

A scientific law describes what occurs every time in a situation.

How is a scientific law different than a scientific theory?

A scientific law is a description of an event or events that occurs every time. A scientific theory, on the other hand, is a proposed explanation for an event. A scientific law does not attempt to explain an occurrence. Rather, it states what happens. A scientific theory attempts to explain why the event takes place, or how the event works. An example of a scientific law is that objects at rest stay at rest unless acted on by an outside force. An example of a scientific theory would be Darwin's theory of evolution in which he explains how species evolve.

What is the difference between an observation and an inference?

An observation is made through the use of the five senses. It is something seen, smelled, heard, touched, or tasted. An inference is a possible explanation or a deduced possible consequence for the observation.

Which of the following is an observation and not an inference?

Bubbles form when two chemicals are mixed together.

Scientific experiments must be able to be repeated by multiple scientists to verify the results that are obtained. Which of the following is an example of a scientific question that could be used to create an easily reproducible experiment?

Does sugar or salt have a greater effect on plant growth?

Why is it important for a researcher to know all safety procedures and where all safety equipment is stored even if they never have an accident?

Even a researcher who is perfectly safe is at risk from accidents caused by other people in the lab. If a lab partner spills chemicals that splash around, they might not be the only one in danger. Therefore it is important for all people working in a lab to know how to respond in emergency situations.

It is rare to prove a hypothesis as incorrect through experimentation.

F

Safety equipment like fire extinguishers and fire blankets are used to prevent accidents.

F

There is only one tool used to heat equipment in the laboratory.

F

What are the two pieces of safety equipment used to respond to fires in the lab?

Fire extinguishers and fire blankets are used to put out fires in lab. Fire blankets are specifically used to put out fires on people.

Julia notices that the "check engine" light comes on while driving her car on days with temperatures of over 100 degrees. What could be a plausible explanation for this?

Her engine overheats when the temperature outside is over 100 degrees.

A student is conducting an experiment to determine how far a ball will roll down a ramp based on the angle of incline. What are three possible controls for this experiment?

Possible answers include, the ramp, the ball, the distance on the ramp from which the ball is released, the amount of air resistance, and so on.

A valid hypothesis must be testable.

T

Scientific theories are subject to change.

T

There is more than one kind of balance used in the laboratory.

T

Describe how the meniscus is used to read volume measurements on a graduated cylinder.

The liquid in a graduated cylinder curves up at the edge where the liquid meets the wall of the cylinder. This curve in the liquid is called the meniscus and is used to determine the volume of liquid in a graduated cylinder by observing the measurement tick closest to the bottom of the meniscus.

What is the difference between the question and hypothesis steps in scientific inquiry?

The question step provides the question to be studied, while the hypothesis step provides a proposed answer to the question.

During the summer, after a big storm blows through, David notices leaks from his air conditioner. Which of the following is the best explanation of the contributing factor for this problem?

The storm damaged the air conditioner.

Scientific experiments are specially designed to test explanations for an observed phenomenon. A student decides to conduct an experiment to determine the effect that the amount of time spent in the sunlight has on the overall growth of a plant. The student will conduct the experiment using two identical plants that will only spend different amounts of time in the sunlight. All other aspects needed for growth will remain identical for each. In the experiment described, what would the amount of water given to each plant be considered?

a control or constant

Which of the following is not used to hold liquids?

balance

Scientists use different types of microscopes to observe objects that are not visible to the naked eye. A scientist is reviewing various samples of pond water to determine what species of microorganisms live in the pond. The scientist wishes to make drawings of the structure of each microorganism and study each one's method of movement. Which of the following microscopes would be best for the scientist to use?

compound light microscope

An independent variable is

directly changed by the experimenter.

Various pieces of safety equipment are used in the lab to provide protection against injury. Which of the following pieces of lab safety equipment is least likely to be used if proper eye goggles are being worn?

eye wash station

A statement that can be proven by observation or measurement is known as a(n):

fact

Many types of scientific equipment are used to perform different functions in the science lab. Which of the following combinations of equipment would be needed to bring one liter of water to 85°C?

graduated cylinder, beaker, thermometer and hot plate

An inference _______.

is a possible explanation for events using prior knowledge

A scientific theory _______.

is an explanation for a set of events

A dependent variable is

manipulated by changes to the independent variable.

Following proper safety guidelines _______.

minimizes the chance of accidents occurring in lab

Fume hoods are used to _______.

prevent toxic gases from spreading through the lab

What are the two categories of observations?

qualitative and quantitative

Which of the following is not used to perform experiments with liquids?

rulers

A transmission electron microscope would be the best microscope choice to study _______.

structures smaller than cells

Scientific questions must be _______.

testable

A student conducts an experiment to determine how the amount of water given to a plant affects its growth. Which of the following is not a constant or control for this experiment?

the amount of water

Which of the following would not be a contributing factor to the life span of goldfish in a backyard pond?

the size of the goldfish