Chapter 2 Measurements and Calculations — Vocabulary Flashcards

Vocabulary flashcards covering key concepts from Sections 2.1–2.8: measurement, scientific notation, SI units, metric prefixes, length/volume/mass, density, uncertainty, significant figures, rounding, dimensional analysis, temperature conversions, and related practice concepts.

Measurement

A quantitative observation that uses numbers and units; the number conveys magnitude and the unit provides the scale.

Scientific notation

A method to express very large or very small numbers as a product of a number between 1 and 10 and the appropriate power of 10.

Positive power of 10 (decimal moved left)

Moving the decimal point to the left yields a positive power of 10.

Negative power of 10 (decimal moved right)

Moving the decimal point to the right yields a negative power of 10.

1 mL = 1 cm³; 1 L = 1 dm³

Equivalences used to relate milliliters to cubic centimeters and liters to cubic decimeters.

International System of Units (SI)

A comprehensive system of units established by international agreement for scientific measurement.

Fundamental SI units

Base quantities with defined SI units: mass (kg), length (m), time (s), temperature (K), electric current (A), amount of substance (mol).

Mass (kilogram, kg)

SI base unit of mass; 1 kg ≈ 2.2046 pounds; 1 pound ≈ 453.59 g.

Length (meter, m)

SI base unit of length.

Time (second, s)

SI base unit of time.

Temperature (kelvin, K)

SI base unit of temperature.

Electric current (ampere, A)

SI base unit of electric current.

Amount of substance (mole, mol)

SI base unit for the amount of substance.

Metric prefixes

Prefixes used to change the size of a unit to express larger or smaller quantities.

Meter (fundamental unit of length)

Fundamental SI unit for measuring length (symbol: m).

Volume

Measure of the amount of 3-D space; SI unit is m³; commonly cm³; 1 mL = 1 cm³; 1 L = 1 dm³.

Density

Mass per unit volume; common units are g/cm³ or g/mL.

Water displacement

Method to determine the volume of a solid by measuring the rise in water level when submerged.

Uncertainty in measurement

A digit that must be estimated; measurements have some uncertainty; certain digits are recorded first, then uncertain digits.

Uncertain digit

The digit in a measurement that is estimated rather than read directly.

Significant figures (general idea)

Digits that carry meaning about precision in a measurement; rules distinguish which zeros are significant.

Leading zeros

Zeros that precede all nonzero digits and are not significant (e.g., 0.048 has two sig figs).

Captive zeros

Zeros between nonzero digits and always significant (e.g., 16.07 has four sig figs).

Trailing zeros

Zeros at the right end of a number; significant only if a decimal point is present (e.g., 9.300 has four sig figs; 150 has two).

Exact numbers

Numbers with unlimited significant figures (e.g., defined constants like 1 inch = 2.54 cm) or counted items.

Exponential notation and sig figs

Scientific notation shows the number of significant figures clearly; helps indicate precision.

Rounding off (Rule 1)

If the digit to be removed is less than 5, the preceding digit stays the same.

Rounding off (Rule 2)

In a series of calculations, carry extra digits to the final result, then round off.

Significant figures in multiplication/division

The result has as many sig figs as the measurement with the fewest sig figs.

Significant figures in addition/subtraction

The result is limited by the term with the smallest number of decimal places.

Dimensional analysis

Problem-solving method using conversion factors to convert units and cancel unwanted units.

Conversion factor

An equivalence between two units used to convert measurements.

Temperature scales (three units)

Fahrenheit, Celsius, Kelvin.

Three major temperature scales

Fahrenheit, Celsius, and Kelvin are used to measure temperature in different contexts.

Converting between temperature scales

Process of converting temperatures among Fahrenheit, Celsius, and Kelvin using standard equations.

Density formula

Density = mass divided by volume; common units include g/cm³ or g/mL.

Volume and mass relationship in SI units

Volume is measured in cubic meters (m³) or cm³; mass is measured in kilograms (kg).