D as the two substances could have close boiling points, so if the temperature is not controlled well, both substances will evaporate.
Alkali metal - Group 1 metal
Alkaline earth metal - Group 2 metal
Iron triad - metal
Halogens - most are diatomic and are nonmetals - Cl2, Br2, I2
Noble gases - nonmetals and are not reactive due to full valence shell.
Boron group - metalloid
Oxygen group - oxygen molecule - a diatomic molecule composed of oxygen atoms, which are nonmetals.
Answer:
Chemical reactions often involve changes in energy due to the breaking and formation of bonds. Reactions in which energy is released are exothermic reactions, while those that take in heat energy are endothermic.
Explanation:
Answer & Explanation: Acid rain occurs when sulfur dioxide and nitrogen oxide are released into the air to create a chemical reaction. When the two mix in the air (oxygen), they will get into the water and mix with other pollutants in the air, making acid rain.
