Senior One Quiz No.1

When a piece of metal is heated and then submerged in cool water, heat is transferred from the metal to the water. This causes the temperature of the water to increase as it absorbs the heat from the metal. At the same time, the metal loses heat to the water, causing its temperature to decrease. Therefore, the correct answer is that the temperature of the water will increase and the temperature of the metal will decrease.

The specific heat of a substance is the amount of heat energy required to raise the temperature of 1 gram of the substance by 1 degree Celsius. In this question, 25 J of heat energy is required to raise the temperature of 5.0 g of substance A by 2.0 degrees Celsius. To find the specific heat, we divide the amount of heat energy (25 J) by the mass of the substance (5.0 g) and the change in temperature (2.0 degrees Celsius). This gives us a specific heat of 2.5 J/g°C, which means that it takes 2.5 Joules of energy to raise the temperature of 1 gram of substance A by 1 degree Celsius.

To convert calories to joules, we need to multiply the number of calories by the conversion factor of 4.18 (1 cal = 4.18 J). In this case, we have 148 calories, so multiplying it by 4.18 gives us 617.44 joules. Since the question asks for the number of joules in 148 calories, the correct answer is 619.

A calorie is larger than a joule because a calorie is a unit of energy commonly used in the field of nutrition, while a joule is the standard unit of energy in the International System of Units (SI). One calorie is equal to approximately 4.184 joules. Therefore, a calorie contains more energy than a joule.

When a thermometer is cooled, the red liquid inside moves down because the glass of the thermometer gets cold. As the glass cools, it contracts, causing the volume inside the thermometer to decrease. This decrease in volume pushes the liquid down, resulting in the movement of the red liquid. The cooling of the glass is the main reason behind the downward movement of the liquid in a thermometer.

The specific heat of a substance is a measure of how much heat energy is required to raise the temperature of a given amount of the substance by a certain amount. In this case, it takes 420 J of heat to raise the temperature of 7 g of olive oil by 30°C. This indicates that olive oil requires less heat energy compared to water to achieve the same temperature change. Therefore, the specific heat of olive oil is less than the specific heat of water.

When heat is released by a chemical system, it means that the system is losing energy in the form of heat. According to the law of conservation of energy, energy cannot be created or destroyed, only transferred or transformed. Therefore, if the chemical system is releasing heat, an equal amount of heat must be absorbed by the surroundings in order to maintain the balance of energy. This is why option a, "absorbed by the surroundings," is the correct answer.

Thermal expansion refers to the property of matter to increase in size when heated. When a substance is heated, its particles gain energy and move more rapidly, causing them to spread out and occupy a larger volume. This phenomenon is observed in various materials, including solids, liquids, and gases. Thermal expansion is utilized in various applications, such as in the design of bridges and buildings to account for changes in size due to temperature fluctuations.

The quantity of heat required to change the temperature of 1 g of water by 1 °C is defined as a calorie. A calorie is a unit of energy commonly used in the field of nutrition and is defined as the amount of heat energy required to raise the temperature of 1 gram of water by 1 degree Celsius. It is often used to measure the energy content of food and beverages.

Shining surfaces, such as polished metals, have high reflectivity, meaning they reflect most of the incoming heat radiation rather than absorbing it. This makes them poor absorbers of heat. Additionally, their smooth surfaces also inhibit the emission of heat radiation, making them poor radiators of heat. Therefore, shining surfaces are both poor absorbers and poor radiators of heat.