Answer:
A student is investigating the affect of different salts on melting points. Four patches of ice of equal size are roped off and a different type of salt is poured on each, one receives table salt (NaCl), one receives Calcium Chloride (CaCl2), one receives Potassium Carbonate (KCO3) and the fourth receives inert sand instead. Each patch receives an equal amount of salt or sand. The student measures the volume of ice remaining and subtracts it from the original volume of ice to see how much melted away. What is a control variable in this experiment?
Theory can be changed based on new research but law is backed up with immense info and is has not been broken once
Answer:
metamorphic-existing rocks are exposed to extreme conditions
sedimentary rock-layers of sediment dry together
igneous rock-magma or lava cools and solidifies.
Explanation: