unit 3 phase changes and heat transfer

Front

What is an endothermic reaction?

Back

An endothermic reaction is a process that absorbs heat from its surroundings, resulting in a decrease in temperature. An example is the dissolution of ammonium chloride in water.

Front

What is an exothermic reaction?

Back

An exothermic reaction is a process that releases heat to its surroundings, causing an increase in temperature. An example is the combustion of fuels.

Front

What happens during the melting phase change?

Back

During melting, a solid turns into a liquid as it absorbs heat. For example, ice melting into water.

Front

What is condensation?

Back

Condensation is the phase change from a gas to a liquid, occurring when gas particles lose energy and come together. An example is water vapor turning into liquid water.

Front

What is the direction of heat flow when touching ice with your hand?

Back

Heat flows from the hand to the ice, causing the ice to melt.

Front

What is freezing?

Back

Freezing is the phase change from a liquid to a solid, occurring when a liquid loses heat. An example is water turning into ice.

Front

What is evaporation?

Back

Evaporation is the phase change from a liquid to a gas, occurring when a liquid gains heat. An example is water turning into steam.

Front

What is sublimation?

Back

Sublimation is the phase change from a solid directly to a gas without becoming a liquid. An example is dry ice turning into carbon dioxide gas.

Front

What is the definition of heat transfer?

Back

Heat transfer is the movement of thermal energy from one object or substance to another, occurring through conduction, convection, or radiation.

Front

What is conduction?

Back

Conduction is the transfer of heat through direct contact between materials, where heat moves from the hotter object to the cooler one.