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)