To test how fertilizer affects aquatic animals, a student prepared four identical containers with water fleas. The student then added different amounts of fertilizer mixed with distilled water to three of three of the containers and distilled water alone to one of the containers. What factor is being tested in this experiment?

The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Which of these is constant for all types of electromagnetic radiation in a vacuum? select one: a. wavelength b. frequency c. photon energy d. amplitude e. velocity

Which sentence indicates that curium is a not a mineral? curium is a chemical element. it is a hard metal that looks like silver in light and glows red in the dark. it was first identified by american scientists working with nuclear energy during world war ii. the scientists, who included glenn seaborg, ralph james, and albert ghiorso, named the element after marie and pierre curie, nobel prize-winning scientists. they found that this human-made element is created when plutonium is bombarded with alpha-particles using a cyclotron. curium is a highly radioactive substance. it is extremely hazardous to human health. on entering the human body, it can hamper the production of red blood corpuscles and cause cancer. however, scientists continue to produce the element for its usefulness in scientific research. for example, it scientists understand the composition of rocks and soil on mars and can also be used to produce thermal energy. scientists have succeeded in producing many curium compounds, such as curium dioxide and curium chloride. these compounds are also used primarily in scientific research.