Question

Dr. Jones has a beaker of water. He adds thermal energy to the water by placing the beaker on a hot plate. What happens to the motion of the water particles as Dr. Jones adds thermal energy to the water?

Option 1: The water particles move more slowly.
Option 2: The motion of the water particles does not change.
Option 3: The water particles stop moving.
Option 4: The water particles move faster.

Answer 1

As Dr. Jones adds thermal energy to the water, the motion of the water particles increases, meaning they move faster.

Step-by-step explanation:

When Dr. Jones adds thermal energy to the water by placing the beaker on a hot plate, the motion of the water particles increases. This is because thermal energy is kinetic energy associated with the random motion of atoms and molecules. An increase in the thermal energy raises the object's temperature, leading to faster movement or vibration of the atoms and molecules. Since water molecules in the beaker will gain energy, this makes Option 4 correct: The water particles move faster.

Moreover, according to thermal energy and temperature relationships, when the atoms and molecules in an object move or vibrate quickly, they have a higher average kinetic energy, and the object is considered 'hot.' Conversely, atoms and molecules in a 'cold' object move more slowly and have lower average kinetic energy. Therefore, adding heat to the beaker of water increases the temperature and the average kinetic energy of the water molecules, resulting in faster movement.