A Science Quiz For Class 4 Students!

Plants grow from seeds. When a seed is planted in soil with the right conditions—water, warmth, and sunlight—it begins to germinate and develop roots, stems, and leaves. This is how most flowers, trees, vegetables, and grasses begin their life cycle. The other options—ant, donkey, TV, and caterpillar—either come from eggs or are man-made objects, not from seeds. Seeds are unique to plants in the natural world.

The three traditional states of matter include solids, liquids, and gases. A solid has a definite shape and volume, a liquid has a definite volume but changes shape to fit its container, and a gas has neither definite volume nor shape, expanding to fill the space available. Heat, on the other hand, is not a state of matter; it is a form of energy that is transferred between substances or systems due to a temperature difference. Heat can influence the state of matter, such as melting a solid into a liquid or evaporating a liquid into a gas, but it is not itself a state of matter.

Saturn is famous for its spectacular rings, which are easily visible through a small telescope and are one of the most recognizable features in our solar system. These rings are made up of millions of ice particles, as well as rocky debris and dust. Each particle orbits Saturn independently, and the rings themselves can be miles thick. Although other planets like Jupiter, Neptune, and Uranus also have ring systems, none are as prominent or as well-known as Saturn’s.

During the monsoon season, there is typically more rainfall and moisture in the air. This creates ideal conditions for the formation of rainbows. Rainbows occur when sunlight is refracted and reflected by water droplets in the atmosphere, and the abundance of rain during the monsoon season increases the chances of these water droplets being present. 

Living things have certain characteristics that distinguish them from non-living things. They grow, reproduce, need food or energy, respond to their environment, and are made up of cells. Rocks do not exhibit these characteristics and are therefore classified as non-living things.

When a coin is dropped in a glass of water, it will sink. The density of the coin is greater than the density of water. Objects with a higher density than the liquid they are placed in will sink, while objects with a lower density will float. Since the coin is denser than water, it will displace less water than its own weight, causing it to sink to the bottom of the glass.

Wool is obtained from animals, particularly sheep, and is commonly used to make clothing. It is a natural fiber that is soft and warm and has excellent insulating properties. Wool is known for its ability to regulate body temperature, making it suitable for various climates. It is a popular choice for winter clothing due to its warmth and moisture-wicking properties. Additionally, wool is durable and has good elasticity, making it a versatile material for clothing production.

Evaporation is the process in which a substance changes from its liquid state to the gaseous state. This occurs when the substance absorbs enough heat energy to overcome the intermolecular forces holding its molecules together. As a result, the molecules gain enough energy to escape into the surrounding air, forming a vapor. Evaporation commonly occurs at the surface of a liquid, and it is a key component of the water cycle, as well as many industrial and everyday processes.

Condensation refers to the process of a substance changing from a gaseous state to a liquid state. This occurs when the temperature of a gas is lowered, causing the gas molecules to lose energy and come closer together, forming a liquid. Condensation is commonly observed when warm air comes into contact with a cooler surface, such as when water vapor in the air condenses on a cold window.

During photosynthesis, plants absorb carbon dioxide (CO2) and water (H2O) and convert them into glucose and oxygen (O2). This process occurs in the presence of sunlight and chlorophyll, a pigment in the leaves. The glucose serves as energy or food for the plants, while the oxygen is released into the atmosphere as a by-product. This oxygen release is crucial for the survival of most life forms on Earth as it contributes to the breathable atmosphere.

The phases of the Moon are caused by the changing positions of the Moon in relation to the Earth and the Sun. As the Moon orbits the Earth, different portions of its surface are illuminated by the Sun, resulting in the various phases, from new moon to full moon. This cycle repeats approximately every 29.5 days. It is a common misconception that the phases are caused by Earth’s shadow; that only occurs during a lunar eclipse.

Sublimation is the correct answer because it refers to the process in which a substance transitions directly from a solid state to a gaseous state, without passing through the liquid state. This occurs when the substance is heated and the vapor pressure exceeds the atmospheric pressure. Examples of substances that undergo sublimation include dry ice (solid carbon dioxide) and mothballs (solid naphthalene). Evaporation, on the other hand, is the process in which a liquid changes into a gas at a temperature below its boiling point, while melting is the process in which a solid changes into a liquid. Filtration is a completely unrelated process used to separate solid particles from a liquid or gas.

Food consumed by living things is a type of fuel because it provides energy for the body to function. Just like petrol fuels vehicles, food fuels living beings by providing the necessary nutrients and calories that are converted into energy through metabolic processes. This energy is then used for various bodily functions such as movement, growth, and maintenance of body temperature.

In order for mid-air refueling to happen, both planes need to be flying at the same speed. If one plane is flying faster or slower than the other, it would be difficult to maintain a stable position for refueling. Therefore, having the planes flying at the same speed is necessary for successful mid-air refueling.