The magazine says it tested 10 insect repellents in an outside laboratory, where volunteers let deer ticks crawl on them and also exposed themselves to mosquitoes. Six of these repellents earned a recommended rating from Consumer Reports. These six repellents, along with their active ingredients and cost, are:
Evaporation vs. Boiling Boiling occurs when the temperature of the liquid is greater than the boiling point of the substance. Evaporation can occur at any temperature.
Introduce the process of condensation. If students do not know what the process of condensation is, you can tell them it is the opposite of evaporation. In evaporation, a liquid (like water) changes state to become a gas (water vapor). In condensation, a gas (like water vapor) changes state to become a liquid (water). Explain that as water molecules in the air cool and slow down, their attractions overcome their speed and they join together, forming liquid water. This is the process of condensation.