Ks3 Science Quiz Questions And Answers

Red blood cells transport oxygen in the human body. Oxygen is carried by a molecule called hemoglobin present in red blood cells, which binds to oxygen in the lungs and releases it to tissues throughout the body. 

When a substance reaches the freezing point, the molecules within the liquid start to slow down and come closer together. This causes the substance to transition from a liquid state to a solid state, as the molecules arrange themselves into a more organized and rigid structure. Therefore, the correct answer is solid.

Alcohol is known to slow down reaction time because it is a depressant that affects the central nervous system. When consumed, it impairs the brain's ability to send and receive messages, leading to delayed responses and decreased coordination. This can be extremely dangerous, especially when engaging in activities that require quick reflexes, such as driving or operating machinery. Slowed reaction time increases the risk of accidents and injuries, making alcohol a hazardous substance to consume.

During development, a baby is protected by amniotic fluid. This fluid surrounds the fetus in the amniotic sac, acting as a cushion to protect the baby from external shocks or injuries. It also helps in maintaining a stable temperature and providing buoyancy, allowing the baby to move and develop its muscles and limbs. Additionally, the amniotic fluid contains essential nutrients and antibodies that support the baby's growth and development.

When a substance reaches the boiling point, it undergoes a physical change known as vaporization or boiling. This change involves the conversion of a liquid into its gaseous state. As heat is applied, the molecules within the liquid gain enough energy to overcome the intermolecular forces holding them together, causing them to break free and form a gas. This process is characterized by the formation of bubbles and the release of gas molecules into the surrounding environment. Therefore, the correct answer is "liquid to gas".

When Iron and Sulphur are mixed together and heated, a chemical reaction takes place that results in the formation of a new substance called Iron Sulphide. This new substance has different properties and characteristics compared to its individual components. Therefore, this is an example of a compound, which is a substance composed of two or more elements chemically bonded together in a fixed ratio.

Protein is needed for growth and repair of body tissue. Proteins are composed of amino acids, which are the building blocks of tissues in the body. When we consume protein, our body breaks it down into amino acids, which are then used to repair and build new tissues. Protein is particularly important for muscle growth and repair, as well as for the production of enzymes, hormones, and antibodies. Carbohydrates and fats are also important for energy production, but they do not play the same role in tissue growth and repair as protein does.

The given words, Magnesium, Oxygen, Carbon, Neon, and Hydrogen, all represent elements. Elements are substances that cannot be broken down into simpler substances by chemical means. Each of these words represents a different element on the periodic table. Magnesium, Oxygen, Carbon, Neon, and Hydrogen are all single words and therefore represent elements.

Gravity is the force that keeps all the planets in orbit around the sun. Gravity is a fundamental force of nature that causes objects with mass to be attracted to each other. In the case of the planets, the gravitational force between the sun and each planet keeps them in their respective orbits. The sun's massive gravitational pull keeps the planets in a constant state of motion, preventing them from flying off into space.

The liver plays a crucial role in the human body by breaking down toxins and storing food. It acts as a filter, removing harmful substances from the bloodstream and metabolizing them into less harmful forms. Additionally, the liver stores nutrients such as vitamins, minerals, and glucose, which are released as needed to provide energy and maintain the body's functions. Therefore, the liver's primary functions are detoxification and nutrient storage.

Friction is the force that prevents a football from rolling on the grass forever. When the football is in motion, it experiences resistance from the grass surface, which creates a force called friction. This force opposes the motion of the football, causing it to slow down and eventually come to a stop. Without friction, the football would continue to roll indefinitely due to the absence of any other forces acting upon it.

During respiration, the waste products created by a human are carbon dioxide and water. This process occurs in the cells of the body, where glucose is broken down to release energy. Carbon dioxide is produced as a byproduct of this breakdown, and it is transported to the lungs where it is exhaled. Water is also produced as a result of cellular respiration and is eliminated through various bodily processes such as sweating and urination. Therefore, the correct answer is carbon dioxide and water.

When we see an object, it is because certain wavelengths of light are being reflected off the object and into our eyes. In the case of a red shirt, it appears red because it reflects the wavelengths of light that correspond to the color red, while absorbing all other colors. This means that when light hits the shirt, all colors except red are absorbed, and only the red light is reflected back to our eyes, allowing us to perceive the shirt as red.

Salt and water mixed together is an example of a mixture. A mixture is formed when two or more substances are combined physically, without any chemical reaction taking place. In this case, salt and water retain their individual properties and can be easily separated. The salt dissolves in the water, forming a homogeneous mixture. This is different from a compound, which is formed when two or more elements chemically combine, resulting in a new substance with different properties.

A battery stores chemical energy. Chemical energy is the potential energy stored in the bonds between atoms and molecules. In a battery, this energy is released through a chemical reaction, typically involving the flow of electrons from one electrode to another. This flow of electrons can be harnessed to produce electrical energy, which can then be used to power various devices.

The freezing point and the melting point of water occur at the same temperature, which is 0 degrees Celsius or 32 degrees Fahrenheit. At this temperature, water changes from a liquid state to a solid state (freezing) or from a solid state to a liquid state (melting). Therefore, the correct answer is 0 degrees.

The word equation for respiration is "Oxygen + Glucose = Water + Carbon dioxide + Energy." This equation represents the process of cellular respiration, where oxygen is combined with glucose to produce water, carbon dioxide, and energy in the form of ATP. This equation accurately describes the chemical reactions that occur during respiration in living organisms.

Refraction is the bending of light as it passes from one medium to another due to the change in its speed. When light travels through materials of different densities, such as air to water or vice versa, refraction occurs. This can be observed when a straw appears bent in a glass of water or when a pencil placed in a glass of water appears broken. Therefore, the correct answer is refraction.

Red has the longest wavelength in the color spectrum. This is because red light has a lower frequency and lower energy compared to other colors. When light waves pass through a prism, they are separated into different colors based on their wavelengths. Red light has the longest wavelength, followed by orange, yellow, green, blue, indigo, and violet.

Violet is the correct answer because it has the shortest wavelength in the color spectrum. The color spectrum ranges from longer wavelengths (red) to shorter wavelengths (violet), with yellow falling in between. The wavelength of light determines its color, with shorter wavelengths appearing more blue or violet, and longer wavelengths appearing more red. Therefore, violet has the shortest wavelength among the given options.

According to the law of reflection, the angle of incidence is equal to the angle of reflection. Therefore, if the incident light ray produces an angle of incidence of 30 degrees when hitting a mirror, the angle of reflection will also be 30 degrees.

The given acids, hydrochloric acid, nitric acid, and sulphuric acid, will react with magnesium metal to produce the salts magnesium chloride, magnesium nitrate, and magnesium sulphate.

The amplitude of a wave refers to the maximum displacement or distance from the equilibrium position of a wave. In the context of sound waves, the amplitude represents the intensity or loudness of the sound. Therefore, the height of a wave is directly related to the sound produced, making it a suitable measure for sound.

Metamorphic rock is formed through the process of extreme heat and pressure acting on existing rocks. This causes the minerals within the rocks to recrystallize, resulting in a new rock with a different texture and composition. Examples of metamorphic rocks include marble, slate, and gneiss. Igneous rock, on the other hand, is formed from the solidification of molten material, while sedimentary rock is formed from the accumulation and compaction of sediment over time. Therefore, the correct answer is metamorphic rock.

Mass is a measure of how much matter an object contains, and it is commonly measured in grams or kilograms. It represents the amount of substance present in an object, regardless of its location or the force acting on it. The force of gravity on an object is actually its weight, which is different from mass. Density and volume are related to mass but are not the same thing.

When a candle is lit, the stored chemical energy in the wax is converted into heat and light energy. This process is known as combustion, where the heat produced causes the wax to melt and vaporize. The vaporized wax reacts with oxygen in the air, releasing energy in the form of heat and light. Therefore, the correct answer is that stored chemical energy transfers to heat and light.

To calculate a moment, you need to multiply the distance from the pivot by the force exerted on the pivot. This is because moment is the product of force and distance, and it represents the turning effect of the force around the pivot point. By multiplying the distance from the pivot by the force, you can determine the magnitude of the moment.

The frequency of a wave refers to the number of oscillations or cycles it completes in a given time period. It is usually measured in hertz (Hz). In this context, "spitch" seems to be a typographical error and should be "pitch". Pitch is a perceptual property of sound that is closely related to its frequency. So, the correct answer is that frequency measures the number of oscillations in a wave as pitch.

This statement suggests that there is a relationship between the number of hours spent revising for an exam and the assessment results. It implies that the more time spent revising, the better the results are likely to be. The statement does not mention any specific variable being dependent or independent, but it indicates a connection or association between the two variables. Therefore, the correct answer is "Relationship."

Fat provides the most energy per gram compared to protein and carbohydrates. While protein and carbohydrates provide 4 calories per gram, fat provides 9 calories per gram. This is because fat molecules contain more carbon and hydrogen atoms, which can be broken down to release more energy during metabolism. Therefore, consuming foods high in fat can provide a higher energy yield compared to foods high in protein or carbohydrates.