NTS NAT flashcards

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

Comma splice

A sentence error in which two independent clauses are joined by only a comma. Repair it with a period, a semicolon, or a coordinating conjunction.

Subject-verb agreement

The verb must match its subject in number. Words or phrases placed between them do not change it, so 'the list of items is' is correct.

Dangling modifier

An introductory phrase that fails to attach to the subject of the main clause, as in 'Walking home, the rain started.' The phrase describes nothing stated.

Its versus it's

'Its' is a possessive determiner showing ownership, as in 'the dog wagged its tail'. 'It's' is only a contraction of 'it is' or 'it has'.

Parallel structure

Items joined by 'and', 'or', or in a list must take the same grammatical form: 'hiking, swimming, and cycling', not a mix of nouns and verb phrases.

Semicolon use

A semicolon joins two independent clauses without a conjunction, and it also separates list items that already contain internal commas.

Root cred-

A Latin root meaning 'believe' or 'trust'. It appears in credible, credit, credulous, incredulous, and credential.

Bridge sentence analogy

A technique for analogy questions: write a precise sentence linking the first word pair, then apply that same sentence to each answer choice.

Denotation versus connotation

Denotation is a word's literal dictionary meaning; connotation is the positive, negative, or neutral feeling attached, as with 'thrifty' versus 'stingy'.

Affect versus effect

'Affect' is usually a verb meaning to influence something. 'Effect' is usually a noun meaning a result or outcome.

Contrast signal words

Words such as 'although', 'despite', 'however', and 'yet' announce a reversal, so the blank normally takes a word opposite in meaning to the clue.

Prefix circum-

A Latin prefix meaning 'around' or 'about'. It appears in circumference, circumnavigate, circumspect, and circumstance.

Percent change formula

Percent change equals (new value minus old value) divided by the old value, then multiplied by 100. A negative result means a decrease.

Mean-sum relationship

The mean of n values equals their sum divided by n. Rearranged, sum equals mean multiplied by n, which reveals a missing total.

Combined work rate

If one worker finishes a job in a hours and another in b hours, working together they complete 1/a + 1/b of the job per hour.

Pythagorean triples

Whole-number right triangles such as 3-4-5, 5-12-13, and 8-15-17, plus their multiples. Recognising them avoids computing square roots.

Slope formula

Slope equals the change in y divided by the change in x between two points. Horizontal lines have slope 0; vertical lines have undefined slope.

Compound interest formula

A = P(1 + r/n)^(nt), where P is the principal, r the annual rate as a decimal, n the compounds per year, and t the years.

Independent event probability

For two independent events, multiply the separate probabilities: the chance both occur equals P(A) times P(B).

Contrapositive

The equivalent form of 'If P then Q', namely 'If not Q then not P'. Unlike the converse, it always carries the same truth value as the original.

Modus tollens

A valid argument form: if P implies Q, and Q is false, then P must also be false. Denying the consequent is legitimate reasoning.

Affirming the consequent

An invalid argument that reasons from 'if P then Q' and Q to the conclusion P. The result may arise from some other cause.

Necessary versus sufficient

A necessary condition must hold for the outcome to occur; a sufficient condition guarantees it. Being a mammal is necessary but not sufficient for being a dog.

Unless translation

'P unless Q' translates to 'if not Q then P', which is also equivalent to 'if not P then Q'. Translating first usually dissolves the trick.

Converse of all-statement

'All A are B' does not imply 'All B are A'. It supports 'Some B are A' only when A is known to contain at least one member.

Ohm's law

Voltage equals current multiplied by resistance, V = IR. Power dissipated in the same component equals voltage times current, P = VI.

Newton's second law

The net force on an object equals its mass times acceleration, F = ma. Weight is the gravitational force, w = mg.

Mole-mass relationship

The number of moles equals mass in grams divided by molar mass. One mole contains 6.02 x 10^23 particles of that substance.

pH definition

pH equals the negative logarithm of the hydrogen-ion concentration. Values below 7 are acidic, values above 7 are basic, and 7 is neutral.

Photosynthesis equation

Six carbon dioxide molecules plus six water molecules, using light energy, yield one glucose and six oxygen: 6CO2 + 6H2O -> C6H12O6 + 6O2.

Accounting equation

Assets equal liabilities plus owner's equity. Every transaction preserves this balance, which is the foundation of double-entry bookkeeping.

Binary place values

Each binary digit stands for a power of two. Reading right to left, the place values are 1, 2, 4, 8, 16, 32, 64, and 128.