If you left a block of dry ice in a bowl at room temperature all day, it would gradually sublimate, turning from a solid into carbon dioxide gas. This process occurs because dry ice is frozen carbon dioxide, and at temperatures above -78.5°C (-109.3°F), it does not melt into a liquid but instead transforms directly into gas.
As the dry ice sublimates, you would likely notice fog forming around the bowl. This fog is created when the cold carbon dioxide gas comes into contact with the warmer air, causing the moisture in the air to condense and form tiny water droplets. If you keep the dry ice in a well-ventilated area, the gas will disperse safely into the atmosphere. However, it’s essential to avoid leaving dry ice in an enclosed space because the buildup of carbon dioxide could lead to asphyxiation.
In summary, leaving a block of dry ice at room temperature results in it gradually turning into gas, creating a chilly fog in the process.