Computer microchips are created from sheets of silicon. These sheets often have an unwanted coating: a thin layer of silica (SiO2). This silica can be removed with hydrofluoric acid (HF). When hydrofluoric acid touches silica, the substances combine to form water (H20) and silicon tetrafluoride gas (SiF4). After the water and gas are removed, the silicon sheet can be processed into microchips. The chemical reaction described in the passage, which of the following are reactants? Select all that apply.
A.) silica (SiO2)
B.) water (H20)
C.) silicon tetrafluoride (SiF4)
D.) hydrofluoric acid (HF)

How do temperature and salinity affect deepwater currents? as temperatures and salinity levels of water increase, the water rises to the surface where it creates currents as it moves to colder regions. they create changes in wind direction, moving denser water in the same direction as the wind and causing the deepwater circulation patterns found in the ocean. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water. they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them.