CHM Ch 2

Flashcards covering key vocabulary related to measurement, scientific notation, units, significant digits, unit conversion, density, and temperature scales from the lecture notes.

Measurement

A foundation of good science, essential in many fields, requiring understanding limits and clear communication.

Scientific Notation

A way to express very large and very small numbers in a concise format using a coefficient and a multiplier (10 raised to an exponent).

Coefficient (Scientific Notation)

The part of a number in scientific notation written with only one digit before the decimal point.

Multiplier (Scientific Notation)

The part of a number in scientific notation represented as 10 raised to an exponent (10x), which shifts the decimal point to the left or right.

Exponent (Scientific Notation)

Indicates how many spaces the decimal point must be moved when converting to standard notation.

Positive Exponent (Scientific Notation)

Represents large numbers, where the decimal point moves to the right.

Negative Exponent (Scientific Notation)

Represents small numbers, where the decimal point moves to the left.

Proper Scientific Notation

A number in scientific notation where the coefficient has only one nonzero digit before the decimal point.

Units of Measurement

Quantities with accepted values that can be communicated between people, such as pounds, cups, or meters.

English Units

A system of measurement commonly used in the United States, including units like inches, feet, gallons, and pounds.

Metric System

A system of measurement used by most of the world.

SI Units

The International System of Units, an accepted set of fundamental units based on the metric system, developed for easier scientific communication.

Derived Unit

A unit formed from combinations of fundamental SI units, such as a liter (volume) or meters per second (velocity).

Metric Prefixes

A series of prefixes used in the metric system to describe larger or smaller amounts, allowing concise expression of very large or small numbers (e.g., kilo-, milli-, micro-).

Uncertainty in Measurement

An inherent part of science where the last digit in a measurement is an estimated value.

Estimated Value (Measurement)

The last decimal place in a measurement, which is an acceptable estimation.

Caliper

A tool used for much more precise measurements than a tape measure or ruler.

Accuracy

Refers to how reliable measurements are; whether a measurement (or average of measurements) reflects the true value.

Precision

Refers to how finely a measurement is made, or how close groups of measurements are to each other.

Calibrating a Balance

The process of adjusting a laboratory balance to ensure its readings are accurate by testing it with objects of known mass.

Significant Digits (Significant Figures)

The digits contained in a measured value, indicating how precisely a measurement is made.

Meniscus

The slightly curved surface of a liquid (like water) in a narrow glass cylinder, due to adhesion to the glass; volume is read at its bottom.

Exact Numbers

Values for which there is no uncertainty, such as counted values (e.g., seven pennies) or defined relationships (e.g., 1,000 milligrams in a gram).

Dimensional Analysis (Factor-Label Method)

A systematic approach to unit conversions where mathematical operations applied to numbers are also applied to their units to track conversions.

Conversion Factors

Fractions that contain equivalent amounts of different units in the numerator and denominator, used to convert between units without changing the quantity's value.

Volume

The space an object occupies, often measured in units of length raised to the third power (e.g., cm³, m³).

Liter (L)

A common derived unit of volume, defined as 1 cubic decimeter (1 dm³).

Cubic Centimeter (cm³)

A unit of volume equivalent to a milliliter (mL).

Milliliter (mL)

A unit of volume equivalent to 1 cubic centimeter (cm³).

Density

An important physical property defined as the mass of a substance per unit volume (d = m/V).

Fahrenheit Scale

A temperature scale commonly used in the United States.

Celsius Scale

A temperature scale used by most of the world, where the freezing point of water is 0 °C and the boiling point is 100 °C.

Kelvin Scale

A temperature scale used by scientists, where 0 K corresponds to absolute zero, and a unit on the Kelvin scale is the same size as a degree Celsius.