What is the name of the term that describes the conditions that are kept the same between all groups in an experiment?

Which best describes how johannes kepler developed his laws of planetary motion

In water, a strong acid will break down into its component parts. a. completely b. partly c. never in water, a weak base will break down into its component parts. a. completely b. partly c. never

Give a real-world example of an energy transformation that uses two of the following forms of energy: chemical, mechanical, nuclear, gravitational, radiant, electrical, thermal (heat), and/or sound.