IMAT flashcards

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

Contrapositive equivalence

The statement 'if P then Q' is logically equivalent to 'if not Q then not P'. The converse 'if Q then P' and the inverse 'if not P then not Q' are not equivalent to the original.

Validity versus truth

In deductive logic an argument is valid when the conclusion must follow from the premises, regardless of whether those premises are actually true in the real world.

Meaning of 'some' in logic

'Some A are B' asserts that at least one A is B; it does not exclude the possibility that all A are B, and it does not mean 'some are not'.

Necessary versus sufficient condition

A is necessary for B if B cannot occur without A; A is sufficient for B if A guarantees B. Necessary and sufficient are distinct and often confused in reasoning items.

Correlation and causation

Observing that two variables change together does not establish that one causes the other; a hidden third factor or reverse causation may explain the association.

Main idea versus supporting detail

The main idea summarises the whole passage's central claim, whereas a supporting detail is true but local. Options resting on one detail usually fail main-idea questions.

Valid inference from a passage

An inference is acceptable only if the passage's stated content necessarily implies it. True facts from outside the text are not valid grounds for the answer.

Author's tone indicators

Evaluative adjectives, adverbs and hedges such as 'arguably', 'unfortunately' or 'reportedly' signal the author's attitude and separate personal claims from reported ones.

Absolute scope words

Words such as 'all', 'never', 'only' and 'must' make an option strong and easy to falsify; 'some', 'may' and 'often' make it weaker and usually safer.

Italian Unification date

The Kingdom of Italy was proclaimed in 1861, with Rome annexed in 1870. This anchors nineteenth-century European history questions in general knowledge sections.

Prokaryote versus eukaryote

Prokaryotes have no membrane-bound nucleus or organelles and use 70S ribosomes; eukaryotes have a nucleus, membrane-bound organelles and 80S ribosomes.

Mitosis versus meiosis

Mitosis yields two genetically identical diploid cells for growth and repair; meiosis yields four genetically distinct haploid gametes after one replication and two divisions.

Mendel's law of segregation

The two alleles of a gene separate during gamete formation, so each gamete carries only one allele, restoring pairs at fertilisation.

Enzyme denaturation

Above an optimum temperature or at extreme pH, non-covalent bonds holding an enzyme's active site break, changing its shape and abolishing catalytic activity irreversibly.

Sites of cellular respiration

Glycolysis occurs in the cytoplasm, the Krebs cycle in the mitochondrial matrix, and oxidative phosphorylation on the inner mitochondrial membrane using the electron transport chain.

Photosynthesis light reactions

In thylakoid membranes, light energy splits water, releasing oxygen and producing ATP and NADPH, which the stroma's Calvin cycle uses to fix carbon dioxide.

Mole and Avogadro constant

One mole contains 6.022×10^23 particles and equals the mass in grams numerically equal to the relative molecular mass; n equals mass divided by molar mass.

Molar volume at STP

At standard temperature and pressure, one mole of any ideal gas occupies about 22.4 litres, allowing conversion between gas volume and amount in moles.

Le Chatelier's principle

A system at equilibrium shifts to oppose a change: raising pressure favours the side with fewer gas moles, and raising temperature favours the endothermic direction.

pH definition

pH equals the negative logarithm of the hydronium ion concentration. At 25 degrees Celsius a neutral solution has pH 7 because Kw equals 10 to the minus 14.

Limiting reagent rule

Convert all reactant quantities to moles, divide each by its stoichiometric coefficient, and the smallest quotient identifies the reagent that runs out first.

Periodic atomic radius trend

Atomic radius decreases from left to right across a period as nuclear charge grows, and increases down a group as additional electron shells are added.

Newton's second law

The net force on a body equals its mass times its acceleration. Weight is a force equal to mass times gravitational acceleration, about 9.8 newtons per kilogram.

Ohm's law and power

For a conductor at constant temperature, voltage equals current times resistance; electrical power dissipated equals voltage times current, or current squared times resistance.

Conservation of mechanical energy

Without friction or other non-conservative forces, the sum of kinetic and gravitational potential energy stays constant during motion near the Earth's surface.

Snell's law of refraction

When light passes between media, the ratio of the sines of the angles to the normal equals the inverse ratio of refractive indices: n1 sin theta1 equals n2 sin theta2.

Quadratic discriminant

For ax squared plus bx plus c equals zero, the discriminant b squared minus four ac gives two real roots if positive, one if zero, and no real roots if negative.

Logarithm product rule

The logarithm of a product equals the sum of the logarithms of the factors, and the logarithm of a power equals the exponent times the logarithm of the base.

Pythagorean trigonometric identity

For any angle, sine squared plus cosine squared equals one; this follows from the unit circle and underlies most trigonometric simplification in exam problems.

Addition rule for probability

For two events, the probability that at least one occurs equals the sum of their probabilities minus the probability that both occur, correcting for double counting.

Critical angle for total reflection

When light travels from a denser to a less dense medium, total internal reflection occurs for incidence angles whose sine exceeds the ratio of refractive indices.