Which one of the following is also known as Dry ice in its solid form ?

Dry ice is the common name for the solid form of carbon dioxide (CO2) [1]. It is widely utilized in cold chain logistics, industrial cleaning, and biomedical preservation due to its ability to maintain low temperatures. Unlike regular ice, which melts into liquid water, dry ice undergoes sublimation, transitioning directly from a solid to a gas at atmospheric pressure. Other options provided represent different chemical compounds: SiO2 is silicon dioxide, commonly known as silica or quartz [1]; CaO is calcium oxide, frequently referred to as quicklime; and MgO is magnesium oxide, often found in fly ash or minerals. The identification of solid CO2 as dry ice is a standard fact in applied chemistry [1].

Sources

1. [1] https://www.sciencedirect.com/topics/engineering/lime-cycle