General Science

The number of non-metals varies depending on classification criteria. Some sources count 17-18 non-metals (excluding metalloids), while others count 22-23 (including certain elements). The answer of 22 is consistent with some Indian educational board classifications. Elements classified as non-metals include hydrogen, carbon, nitrogen, oxygen, phosphorus, sulfur, selenium, and the halogens (F, Cl, Br, I). The noble gases are sometimes counted separately. The exact count depends on whether metalloids like boron, silicon, and germanium are included.

Light is a form of electromagnetic waves and electromagnetic waves are a type of energy. We can see light almost everywhere. Light is produced and taken in by tiny packets also known as photons and correspondingly, it exhibits properties of waves and particles.

The nucleus of plant cells is usually of a round or elliptic appearance, sometimes it is also shaped like a spindle.

The first part of a plant to grow is the root like a straw, transports water through plant raises the height of flowers and leaves and brings closer to light. Leaves and flowers also grow.

Electric charge comes in two types- positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two negatively charged objects. Positively charged objects and negatively charged objects experience an attractive force. The SI unit of electric charge is the coulomb.

Fractional distillation columns for mixed solvent separation with high purity results-up to 99.5 percent minimum purity for selected products and a water content of under 500 parts per million.

Sodium nitrate is the chemical compound with the formula NaNO₃.

Nasal passage in the nose is present behind the nostrils.

Theophrastus (c. 371-287 BC), a student of Aristotle, is considered the father of botany for his pioneering work 'Historia Plantarum' which systematically described plants. Linnaeus is known as the father of taxonomy, not botany specifically. Mendel is the father of genetics for his work on inheritance in pea plants.

Aluminium is extracted from bauxite (Al2O3) by the Hall-Héroult process, which involves electrolysis of molten aluminium oxide dissolved in cryolite. Molten chlorides are not the source - bauxite is an oxide ore. The key is that alumina must be molten for electrolysis to work.

Diffusion occurs fastest in gases because gas molecules have the most kinetic energy and are far apart, allowing rapid random movement. In liquids, diffusion is slower due to stronger intermolecular forces. In solids, diffusion is extremely slow as particles are fixed in position.

An alloy is a homogeneous mixture of two or more solid elements, where one is a metal. Examples include brass (copper + zinc) and steel (iron + carbon). Air is a gas mixture, alcohol in water is a liquid-liquid solution, not solid-solid.

Covalent compounds are typically nonpolar or weakly polar, making them soluble in organic solvents (like benzene, ether, chloroform) which have similar intermolecular forces. Water is polar and does not dissolve most covalent compounds. Acids may or may not dissolve them depending on reactivity.

The volt (V) is the SI unit of potential difference, defined as one joule per coulomb. Coulomb is the unit of electric charge. Ampere is the unit of electric current. Potential difference measures the work done per unit charge.

A solid solution is a homogeneous mixture of two or more solids where one solid is dissolved in another. Alloy is an example of a solid solution. Solvent is the dissolving medium, solute is what gets dissolved - these are roles, not the solution itself.

An emulsion is a colloidal dispersion of liquid droplets in another liquid (e.g., milk, mayonnaise). Foam is gas in liquid, gel is liquid in solid matrix, smoke is solid particles in gas. Only emulsion fits liquid-in-liquid dispersion.

Litmus, methyl orange, and phenolphthalein are all acid-base indicators that change color depending on pH. Litmus turns red in acid, blue in base. Methyl orange is red in acid, yellow in base. Phenolphthalein is colorless in acid, pink in base. All three are valid indicators.

Ionic compounds have high melting and boiling points due to strong electrostatic forces between oppositely charged ions throughout the crystal lattice. Covalent compounds have weak intermolecular forces, resulting in low melting/boiling points. Ionic bonds require much more energy to break than covalent molecular forces.

The adult human skeleton typically contains 206 bones. This includes axial skeleton (skull, vertebral column, thoracic cage) and appendicular skeleton (limbs, girdles). The number is consistent in healthy adults, though some individuals may have variations due to sesamoid bones or sutural bones.

Biogas comprises primarily methane (CH₄) and carbon dioxide (CO₂) and may have small amounts of hydrogen sulphide (H₂S), moisture and siloxanes. The major component out of all of them is methane.

Formic acid (methanoic acid, HCOOH) is the primary irritant in ant venom, particularly in fire ant stings. It causes the characteristic burning sensation and is named from the Latin word 'formica' meaning ant. The other options (tomatoes, tamarind) contain other organic acids but not formic acid.

None of the given acids is stored in metal containers.

Abundance earth's crust: 200 parts per million by weight.

Aniline dyes are considered synthetic organic compounds, a carbon-based chemical is used as a dye.