Everyday Science

Matter commonly exists in three primary states: solid, liquid, and gas. These are the fundamental states observed under normal conditions. While there are additional states like plasma and Bose-Einstein condensate under extreme conditions, the three states are the most familiar and commonly taught in basic science education.

The primary function of perspiration (sweating) is to regulate body temperature by cooling the skin as sweat evaporates. While perspiration can help remove some waste, temperature regulation is its main role.

Radio waves have the lowest energy among the given options because energy of electromagnetic radiation is inversely proportional to its wavelength. Radio waves have the longest wavelength and thus the lowest energy.

The Sun is the largest natural source of light for Earth, providing the primary illumination and energy. The Moon only reflects the Sun's light, stars are distant and much smaller sources of light from our perspective, and 'None of these' is incorrect.

Eratosthenes was the first known person to accurately measure the Earth's circumference using the angles of shadows in different locations and basic geometry around 240 BCE.

Apples typically contain about 84% water by weight, making option A the correct choice. This high water content contributes to their juiciness and nutritional value.

Potassium metabisulphite is commonly used as a preservative in fruit juices to prevent oxidation and microbial growth, thereby extending shelf life. It acts as an antioxidant and antimicrobial agent, making it suitable for preserving fruit juices.

Mass is the quantity of matter present in an object, distinguishing it from weight, which depends on gravitational force. Density relates mass to volume, so it is not the direct measure of quantity of matter.

Soil acidity is commonly corrected by liming, which involves adding lime (calcium carbonate) to neutralize acidic soils and increase pH levels. This method is widely used in agriculture to improve soil quality.

Red, blue, and yellow are the traditional primary colors in the subtractive color model used in art and everyday science. Green is a secondary color made by mixing blue and yellow, so it is not a primary color.

Golden rice is genetically engineered to produce beta-carotene, a precursor of vitamin A, to help combat vitamin A deficiency. Therefore, it contains the highest quantity of vitamin A compared to other vitamins listed.

Magnesium is commonly extracted from seawater because it is abundant in dissolved form as magnesium chloride. Potassium and aluminum are not typically extracted from seawater on a commercial scale.

LPG (Liquefied Petroleum Gas) mainly consists of propane and butane, with butane being a major constituent. Methane and ethane are more common in natural gas, and hydrogen is not a component of LPG.

Gold is known for its non-toxic nature and biocompatibility, which is why it is often used in medical implants and dental work. Other metals like silver, iron, and copper can be toxic in certain forms or concentrations.

The heat from the sun reaches the earth primarily through radiation, as it travels through the vacuum of space without the need for a medium. Convection and conduction require a medium and cannot occur in space.

The term "white coal" is a traditional nickname for hydroelectric power because it harnesses the energy of flowing water, similar to how coal is used for energy, but without pollution. Hence, hydroelectricity is correctly referred to as "white coal."

A solid is a state of matter that has a definite shape and volume because its particles are closely packed in a fixed arrangement, unlike liquids and gases which do not have a fixed shape.

Vitamin C is absent in cheese, milk, and rice, so none of these foods contain vitamin C. Therefore, the correct answer is 'None of these' as all listed foods lack vitamin C.

The process of crushing kidney stones using shock waves is called lithotripsy. Laparoscopy is a surgical technique, dementia is a neurological condition, and 'None of these' is incorrect.

Neem tree is well known for its mosquito repellent properties, and many mosquito repellent creams use extracts derived from neem as the chief ingredient to repel mosquitoes effectively.

The organic group of minerals is characterized by the presence of hydrocarbons or compounds containing carbon and hydrogen. Silicate, oxide, and hydride groups do not chemically contain hydrocarbons.

Sea water freezes at a lower temperature than fresh water due to the dissolved salts it contains. Fresh water freezes at 0°C (32°F), while typical sea water freezes at about -1.8°C (28.4°F). The salt ions disrupt the formation of ice crystals, lowering the freezing point. Therefore, sea water freezes at a slightly lower temperature than fresh water, not the same or higher temperature.

Most gases conduct electricity when they are at very low pressure because the reduced number of gas molecules allows free electrons to move more easily, enabling electrical conduction. At normal or very high pressures, gases are poor conductors of electricity.

The characteristic odor of garlic is due to sulfur compounds, primarily allicin, which contains sulfur atoms responsible for its distinctive smell.

Cooking gas, commonly known as LPG (liquefied petroleum gas), is primarily a mixture of propane and butane, not the gases listed in options A, B, or C. Therefore, 'None of these' is the correct choice.