Science-heat And Temperature Quiz (Grade 7)

The boiling point for water on the Celsius scale is 100 degrees. This means that at this temperature, water changes from a liquid state to a gaseous state. It is a well-known fact in science that water boils at 100 degrees Celsius under normal atmospheric pressure.

Radiation can come from various sources, including Britney Spears, a chocolate bar, a broken lightbulb, a wall, and the Sun. The Sun is a significant source of radiation as it emits various forms of electromagnetic radiation, including visible light, ultraviolet (UV) radiation, and infrared radiation. These forms of radiation are essential for sustaining life on Earth, but excessive exposure to UV radiation can be harmful. Therefore, it is crucial to protect oneself from the Sun's radiation by using sunscreen and wearing protective clothing.

The given statement is a correct explanation of the particle model of matter. According to this model, all substances are composed of tiny particles that are too small to be seen with the naked eye. These particles are in constant motion and have spaces between them. This explanation aligns with the scientific understanding of matter and its composition at the microscopic level.

Fossil fuels are considered non-renewable because they are formed from ancient organic materials such as plants and animals that have been buried and subjected to heat and pressure over millions of years. These resources, including coal, oil, and natural gas, are finite and cannot be replenished within a human lifespan. As a result, their extraction and consumption contribute to environmental concerns such as air pollution and climate change. It is important to explore and develop alternative, renewable energy sources to reduce our dependence on fossil fuels.

Temperature is a measure of the average kinetic energy of particles in a substance, indicating how hot or cold the substance is. Heat, on the other hand, refers to the energy transferred between substances or objects due to a temperature difference. It flows from a hotter object to a cooler one until thermal equilibrium is reached. They are related but distinct concepts, and cannot be used interchangeably, as stated in option B.

Plasma is the correct answer because it is the fourth universal state of matter. Plasma is a highly ionized gas that consists of free electrons and positive ions. It is often referred to as the "fourth state of matter" because it exhibits unique properties that are distinct from solids, liquids, and gases. Plasma is commonly found in stars, lightning, and fluorescent lights, and it plays a crucial role in various natural and technological processes.

Sublimation is the process in which a gas directly transforms into a solid without passing through the liquid state. This occurs when the temperature and pressure conditions are such that the gas molecules lose enough energy to form a solid. The other options, freezing, evaporation, and condensation, all involve the transformation of a substance from one state to another, but not specifically from gas to solid. Pemmican is not related to the process of gas turning into a solid.

Chemical energy refers to the potential energy stored in the bonds of chemical compounds, such as coal and wood. When these compounds undergo a chemical reaction, such as combustion, the stored energy is released in the form of heat and light. Therefore, the energy from coal and wood represents chemical energy.