CHE102 Lecture 1: Chemistry and Measurements (SI Units, Prefixes, Notation, and Significant Figures)

Vocabulary flashcards covering core concepts from CHE102 Lecture 1: matter, measurements, SI units, prefixes, scientific notation, significant figures, and dimensional analysis.

Matter

Anything that has mass and volume.

Chemistry

The study of matter and its properties.

Chemical

A substance with a definite composition and properties wherever found.

Qualitative Analysis

Study of properties using non-numeric observations (color, smell, texture).

Quantitative Analysis

Study of properties using numerical measurements (mass, length, volume, temperature).

SI Units

Standard units used in science, comprising seven base units and numerous derived units.

Base Unit – Mass

Kilogram (kg).

Base Unit – Length

Meter (m).

Base Unit – Time

Second (s).

Base Unit – Temperature

Kelvin (K).

Base Unit – Amount of Substance

Mole (mol).

Base Unit – Electric Current

Ampere (A).

Base Unit – Luminous Intensity

Candela (cd).

Derived Unit – Area

Square meter (m^2).

Derived Unit – Volume

Cubic meter (m^3).

Derived Unit – Density

Kilogram per cubic meter (kg/m^3).

Derived Unit – Velocity

Meter per second (m/s).

Decimal Prefixes

Prefixes used with SI units to denote powers of ten (e.g., mega, kilo, milli).

Mega (M)

10^6 (one million).

Kilo (k)

10^3 (one thousand).

Deci (d)

10^-1 (0.1).

Centi (c)

10^-2 (0.01).

Milli (m)

10^-3 (0.001).

Micro (μ)

10^-6 (0.000001).

Nano (n)

10^-9 (0.000000001).

Scientific Notation

A = decimal part × 10^exponent, with the decimal part between 1 and 10.

Scientific Notation – Decimal Part

Must be ≥1 and <10.

Scientific Notation – Exponent

Exponent adjusted when moving the decimal to keep the decimal part within [1,10).

Significant Figures (sf)

Digits that carry meaning contributing to precision of a measurement.

Significant Figures Rule – Addition/Subtraction

Result rounded to the least precise decimal place. (Based on where the last significant digit is.)

Significant Figures Rule – Multiplication/Division

Result has as many sf as the factor with the fewest sf.

Propagation of Error

Last digits are uncertain; uncertainty carried through calculations.

Conversion Factor

A ratio used to convert one unit to another (e.g., 1 kg = 2.205 lb).

Dimensional Analysis

Problem-solving method using conversion factors to cancel units.

Eggs Example (Dozen)

12 eggs = 1 dozen; used to illustrate conversion factors.

Unit Conversions in Chemistry

Frequent conversions between SI units (e.g., 1000 m = 1 km = 1×10^6 mm).