Ontario Grade 9 Science Class Practice Exam 2025 – Your Complete Guide to Exam Success!

The three types of heat transfer are conduction, convection, and radiation.

Conduction involves the transfer of heat through direct contact between materials. When you touch a hot stove, heat moves from the stove to your hand, demonstrating conduction. This process occurs in solids where particles are closely packed and can easily transfer energy by colliding with one another.

Convection is the transfer of heat through fluids (liquids and gases) caused by the movement of the fluid itself. As a fluid heats up, it becomes less dense and rises, while cooler, denser fluid sinks. This creates a convection current, which is responsible for various phenomena, such as the heating of water in a pot or the warming of air in a room.

Radiation, on the other hand, involves the transfer of heat through electromagnetic waves, which can occur in a vacuum as well as in the atmosphere. This is how the Sun warms the Earth; it emits energy that travels through space and warms up the ground and air upon reaching them.

Understanding these three processes provides foundational knowledge in thermal dynamics and can explain everyday phenomena, from cooking to weather patterns.