Chemistry Vocabulary Flashcards - CHM 101 Notes (Chapter 1)

Vocabulary flashcards covering key terms from the lecture notes on matter, energy, measurement, and SI units.

Matter

Anything that has mass and takes up space.

Substance

Matter with a fixed composition and properties that do not vary from sample to sample.

Pure substance

A substance with a fixed composition (an element or a compound).

Element

A substance that cannot be decomposed into simpler substances.

Atom

The basic building block of matter; smallest unit of an element.

Molecule

Two or more atoms bound together in a definite arrangement.

Compound

A substance composed of two or more elements; its molecules contain more than one kind of atom.

Mixture

A combination of two or more substances whose components retain properties.

Homogeneous mixture (solution)

Uniform composition throughout; components are not visibly distinguishable.

Heterogeneous mixture

Not uniform throughout; components are visibly different.

Law of Constant Composition

The elemental composition of a compound is always the same.

States of Matter

Matter exists as gas, liquid, or solid.

Gas

No fixed shape or volume; fills the container; particles are far apart and move quickly.

Liquid

Fixed volume but no fixed shape; takes shape of container; molecules flow.

Solid

Definite shape and volume; particles are rigidly arranged.

Physical property

Observed without changing the substance (e.g., boiling point, density).

Chemical property

Observed during a chemical change (e.g., flammability, reactivity).

Physical change

A change that alters form or state but not the composition.

Chemical change

A process that results in new substances formed.

Intensive property

Property that does not depend on the amount of substance.

Extensive property

Property that depends on the amount of substance.

Kinetic energy

Energy of motion; Ek = 1/2 mv^2.

Potential energy

Stored energy due to position.

Energy

The ability to transfer heat or perform work.

Temperature

Measure of hotness or coldness; determines heat flow direction.

Celsius (°C)

Temperature scale where 0°C is the freezing point and 100°C is the boiling point of water.

Kelvin (K)

SI temperature unit; 0 K is absolute zero; K = °C + 273.15.

Absolute zero

Lowest possible temperature, 0 K.

Mass

Amount of matter in an object; SI base unit is the kilogram.

Length

Distance; base SI unit is the meter.

Volume

Amount of space occupied; derived from length; 1 L = 1000 mL; 1 cm^3 = 1 mL.

Density

Mass per unit volume; common units are g/mL or g/cm^3.

Joule (J)

SI unit of energy; 1 J = 1 kg·m^2/s^2.

Watt (W)

SI unit of power; 1 W = 1 J/s.

Calorie

Energy unit; 1 cal = 4.184 J.

Significant figures

Digits that carry meaningful precision; rules govern which zeros count.

Exact numbers

Counts or definitions with infinite significant figures (e.g., conversion factors).

Accuracy

Proximity of a measurement to the true value.

Precision

Proximity of several measurements to each other.

Uncertainty

Inaccuracy inherent in any measurement due to instrument limits.

Scientific notation

Writing numbers as a coefficient between 1 and 10 times a power of 10.

Dimensional analysis

Method to convert units using conversion factors.

Conversion factor

A ratio that equals 1, relating two units.

Metric prefixes

Prefixes that denote powers of ten (e.g., kilo- = 10^3, milli- = 10^-3, etc.).

Peta (P)

10^15; used for very large quantities.

Tera (T)

10^12.

Giga (G)

10^9.

Mega (M)

10^6.

Kilo (k)

10^3.

Deci (d)

10^-1.

Centi (c)

10^-2.

Milli (m)

10^-3.

Micro (μ)

10^-6.

Nano (n)

10^-9.

Pico (p)

10^-12.

Femto (f)

10^-15.

Atto (a)

10^-18.

Zepto (z)

10^-21.