AP SSC General Science (BSEAP) flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

Mirror formula

For a spherical mirror, 1/v + 1/u = 1/f, where u is object distance, v image distance, and f focal length, all measured from the pole with proper sign convention.

Magnification of mirror

The ratio of image height to object height, m = h'/h = −v/u. A negative value indicates a real inverted image; a positive value indicates a virtual erect image.

Convex mirror image

A convex mirror always forms a virtual, erect, and diminished image located behind the mirror between its pole and focus, which is why it is used as a rear-view mirror.

Balanced chemical equation

An equation in which the number of atoms of each element is equal on both reactant and product sides, satisfying the law of conservation of mass during a chemical reaction.

Redox reaction

A reaction in which oxidation, the loss of electrons or gain of oxygen, and reduction, the gain of electrons or loss of oxygen, occur simultaneously, for example zinc reacting with copper sulphate.

pH scale

A scale from 0 to 14 measuring hydrogen ion concentration. Values below 7 are acidic, 7 is neutral, and above 7 is basic; lower pH means higher H+ concentration.

Neutralisation reaction

A reaction between an acid and a base producing salt and water, such as hydrochloric acid plus sodium hydroxide giving sodium chloride and water, releasing heat.

Water of crystallisation

Fixed number of water molecules present in one formula unit of a crystalline salt, as in blue copper sulphate pentahydrate, which turns white on heating.

Snell's law

For light passing between two media, the ratio of the sine of the angle of incidence to the sine of the angle of refraction equals the refractive index of the second medium relative to the first.

Total internal reflection

When light travels from a denser to a rarer medium at an angle of incidence greater than the critical angle, it is completely reflected back into the denser medium.

Refractive index

The ratio of the speed of light in vacuum to its speed in a given medium; also equal to the sine of the angle of incidence divided by the sine of the angle of refraction.

Accommodation of eye

The ability of the eye lens to change its focal length through the action of ciliary muscles, allowing clear vision of objects at different distances from the eye.

Myopia correction

Short-sightedness, in which the image of a distant object forms in front of the retina, is corrected by placing a concave lens of suitable power before the eye.

Dispersion of light

The splitting of white light into its component colours, VIBGYOR, when it passes through a prism, because each colour has a different refractive index.

Mass number

The total number of protons and neutrons present in the nucleus of an atom, denoted by A, while the atomic number Z counts only the protons.

Isotopes

Atoms of the same element having the same atomic number but different mass numbers, because they contain different numbers of neutrons, such as chlorine-35 and chlorine-37.

Valency

The combining capacity of an element, equal to the number of electrons it loses, gains, or shares to achieve a stable noble gas configuration in its outermost shell.

Modern periodic law

The properties of elements are a periodic function of their atomic number, which forms the basis of the modern periodic table with seven periods and eighteen groups.

Ionic bond

A bond formed by complete transfer of one or more electrons from a metal atom to a non-metal atom, creating oppositely charged ions held by strong electrostatic attraction.

Covalent bond

A bond formed by sharing of one or more pairs of electrons between two non-metal atoms, each contributing electrons to complete its octet, as in water and methane.

Ohm's law

At constant temperature, the current through a conductor is directly proportional to the potential difference across its ends, giving the relation V = IR.

Fleming's left-hand rule

With thumb, forefinger, and middle finger of the left hand mutually perpendicular, forefinger shows magnetic field, middle finger current, and thumb the force on the conductor.

Roasting and calcination

Roasting heats a sulphide ore strongly in excess air to form oxide; calcination heats a carbonate ore in limited air to drive off carbon dioxide and form oxide.

Froth flotation

A concentration method in which powdered sulphide ore is agitated with water, oil, and froth, so the ore particles rise with froth while gangue settles below.

Homologous series

A family of organic compounds with the same functional group, in which successive members differ by one CH2 unit and 14 mass units, showing gradually changing properties.

Esterification

The reaction of a carboxylic acid with an alcohol in the presence of a small amount of acid catalyst, producing an ester with a sweet smell and water.

Mendel's law of segregation

The two alleles of a gene separate during gamete formation so that each gamete receives only one allele, restoring the pair at fertilisation.

Natural selection

The process in which individuals with variations better suited to their environment survive and reproduce more successfully, gradually changing the characteristics of a population over generations.

Reflex action

A rapid, automatic, involuntary response to a stimulus, such as pulling the hand away from a hot object, mediated by a reflex arc through the spinal cord.

Double fertilisation

In flowering plants, one male gamete fuses with the egg to form the zygote and the second fuses with the polar nuclei to form triploid endosperm.

Placenta

A disc-shaped tissue connecting the developing embryo to the uterine wall, allowing exchange of nutrients, oxygen, and waste between mother and fetus.

Ozone layer

A region of the stratosphere containing ozone gas that absorbs most harmful ultraviolet radiation from the Sun, protecting living organisms from skin damage and mutation.

Biomagnification

The progressive increase in concentration of a harmful non-biodegradable substance, such as a pesticide, at each successive trophic level of a food chain.