Heat And Temperature Quiz With Answer

Heat flows from hot to cold due to the principle of the second law of thermodynamics. According to this law, heat naturally moves from a region of higher temperature to a region of lower temperature until both regions reach thermal equilibrium. This process occurs because the molecules in a hotter substance have more kinetic energy and collide with the molecules in a colder substance, transferring energy and increasing their temperature. Therefore, heat transfer always occurs in the direction of hot to cold.

The statement correctly defines specific heat capacity as the amount of heat needed to raise the temperature of a given mass of a substance by 1 degree Celsius. Therefore, the answer "True" is correct.

Heat transfer occurs when there is a temperature difference between two objects or substances. In order for heat to transfer, there needs to be thermal contact between the objects or substances involved. This means that they must be in direct physical contact or connected by a medium that allows the transfer of heat, such as a solid, liquid, or gas. Without thermal contact, heat cannot be transferred from one object to another. Therefore, the statement "heat transfer needs thermal contact" is true.

Internal energy refers to the total energy possessed by a substance, including both its kinetic and potential energies. It encompasses all forms of energy present within the substance, such as the energy associated with the motion of its particles, the potential energy stored in chemical bonds, and the energy due to its temperature. It is not solely limited to the amount of heat required to change the temperature of the substance by 1 degree Celsius or the energy transferred between objects due to a temperature difference.

Thermal equilibrium refers to the state in which two objects are at the same temperature. In this state, there is no net flow of heat between the objects, as they have reached a balance in their thermal energies. This occurs when the rate of heat transfer from one object to another is equal to the rate of heat transfer in the opposite direction.

The internal energy refers to the total amount of energy that is present within an object. This includes all forms of energy such as kinetic energy, potential energy, and thermal energy. It represents the sum of all the microscopic energy particles within the object, including the motion and interactions of its atoms and molecules. The internal energy is a fundamental concept in thermodynamics and is used to study and analyze various physical systems.

In thermal equilibrium, there is no transfer of energy because the temperatures of the objects or systems in contact with each other are equal. This means that there is no temperature difference driving the transfer of heat from one object to another. Therefore, no energy is transferred between the objects, resulting in a state of thermal equilibrium.

When heated, molecules gain energy and move more, causing them to spread out and increase in volume. This expansion is the reason why substances generally expand when heated, rather than contract. Therefore, the statement that "things contract when heated because molecules move more" is incorrect.

Liquids generally expand when heated due to the increased kinetic energy of their particles. However, water is an exception to this rule. As water is heated, it undergoes a unique phase change known as the "anomalous expansion of water." When water is heated from 0°C to 4°C, it actually contracts and becomes denser. This is because the hydrogen bonding between water molecules becomes more ordered, causing the water to take up less space. However, once the temperature exceeds 4°C, water starts to expand like other liquids.

Heat is a form of energy and can be measured in different units. Joules and calories are both commonly used units to measure heat. Therefore, the correct answer is A and C, as both joules and calories are valid units for measuring heat.

Heat is the energy transferred between objects because of a temperature difference. When two objects have different temperatures, heat flows from the object with higher temperature to the object with lower temperature until they reach thermal equilibrium. This transfer of energy is what we perceive as heat. The greater the temperature difference between the objects, the greater the amount of heat transferred.

Calorimeters are devices used to measure the heat transfer in a system, not the internal energy. Internal energy refers to the sum of the kinetic and potential energies of the particles within a substance, while calorimeters measure the heat gained or lost during a chemical or physical process. Therefore, the statement that calorimeters find the internal energy of something is incorrect.

Thermal equilibrium refers to a state where two or more objects or systems are in contact and have the same temperature. In this state, there is no net transfer of heat between the objects, as they are in balance. Therefore, for thermal equilibrium to occur, objects need to be in contact with each other.

The given answer includes three values that represent absolute zeros on different temperature scales. -459 Fahrenheit is the absolute zero on the Fahrenheit scale, 0 kelvin is the absolute zero on the Kelvin scale, and -273 Celsius is the absolute zero on the Celsius scale. These values represent the lowest possible temperature that can be reached, where molecular motion ceases.

Temperature is a measure of how hot or cold something is. It is also related to the average molecular kinetic energy in a substance, as the temperature increases, the average kinetic energy of the molecules increases. Therefore, temperature can be considered as a measure of the kinetic energy of a particle. Temperature can be measured in different units such as Fahrenheit, Celsius, and Kelvin, which are commonly used to quantify temperature.