In science, it is important to be able to distinguish between an experiment and other scientific investigations. Which of the following is the best example of an experiment? measuring the frequency of the fire alarm at your school

measuring the wavelengths of various sources of blue light

measuring the wavelengths of x-rays and gamma rays from Barnard's Star

measuring the change of frequency of a car horn every five meters as the car drives away

Which of the following statements is not true about regions? a.) regions have fixed boundaries that are determined by the region's inhabitants.b.) a region can be defined by physical characteristics, such as climate, landform, and vegetation.c.) regions can change over time.d.) a region can be defined by human characteristics, such as language, government, and economic activity.e.) the same location can be considered part of multiple regions.

Why are radio observatories located in valleys far away from urban centers? a. to shield them from electromagnetic interference b. to avoid sound pollution c. to avoid disturbing people living in the city d. to shield them from water vapor

What is the american psychological association’s ethical principle of psychologists and code of conduct based upon? a. the work of a dozen world-renowned philosophers and ethical savants. b. the feedback of thousands of psychologists and their ethical struggles. c. the regulatory power and authority of the united states constitution. d. the hippocratic rules and guidelines of medical practitioners and surgeons. select the best answer from the choices provided a b c