A scientist sets up an experiment to test which substance (caffeine, nicotine, alcohol, or water) affects plant growth the most. Figure 1 shows how the experiment was set up. The plants, containers/pots, soil, and sunlight were kept the same. Control variables (the things that are kept the same) in this experiment are:

increased stability in the completion of fluorine's outer shell.

a pan containing water is placed in a positio n where it is exposed to a 10 mile per hour wind. the pan contains a uniform depth of 1.27 cm of water, is quite wide, and has a length of 2.44 m in the wind direction. the water in the pan is at a constant temperature of 15.5 °c.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.