Dissolving sugar in water is a physical change: If you evaporate the water from a sugar-water solution, you're left with sugar. So no new products are formed. [Recapitulation: Physical change is the change of that matter where only the appearance or molecular arrangement of matter changes without changing its composition. ... Read More

False. Radiation is the mode of heat transfer that takes place in a vacuum. Conduction and Convection do not occur in Vacuum but Radiation occursTrue. In gases, there are less intermolecular forces are very weak, so they expand easily on heating. In solids, the intermolecular forces are strong so they ... Read More

Black bodies absorb and emit heat the best.

Hello Aditi, The chemical formula of Acetic acid is - CH3COOH (can also be written as CH3CO2H, C2H4O2, or HC2H3O2) also known as ethanoic acid, and the second simplest carboxylic acid. It is a colourless liquid organic compound and has a distinctive sour taste and pungent smell.A dilute (approx 5% by ... Read More

Plant nutrients are those chemical elements that are essential to the nourishment of plant health & growth. Plants get nutrients from three categories, all of which are based on the amount a plant needs. Each nutrient performs a crucial role in plant growth and development. There are two main ... Read More

Fermentation is an enzyme-catalyzed metabolic process in which an organism converts carbohydrates, such as starch or sugar, into alcohol or acid, anaerobically (absence of oxygen) releasing energy.The study of fermentation is called “zymology”. For example, Alcohol / Ethanol Fermentation: It is used in the industrial production of wine, beer, biofuel, ... Read More

Given: 24- carat gold is 100% pure gold.To do: To find the percentage of pure gold in 22 -carat gold.Solution:24-carat gold means 100% puritySo, 22-carat gold means $100 \times \frac{22}{24}$ = $91  \frac{2}{3}%$ or $91.67%$ purity Therefore, the percentage of pure gold in 22 carat of gold is 91.67%

Given: The given expression is $y^{2}+9 y+18 $.To do: Find the value of $y$.Solution:$y^2 + 9y + 18$ $= y^2 + 6y + 3y + 18$[splitting the middle term] = $y(y+6) + 3 (y + 6)$ = $(y + 3) (y + 6)$$ y = -3 \ or -6$ Therefore the value of y is either $-3$ or $-6$

Phenolphthalein is a colourless crystalline solid (pink in alkaline solution) used as an acid-base indicator and medicinally as a laxative.

(i) In a triangle, the sum of any two sides should be greater than the third side.Therefore, 10 cm + 2 cm = 12 cm is equal to the third side 12 cm.Therefore, line segments of length 10 cm, 2 cm and 12 cm cannot form a triangle. (ii) ... Read More