Introduction to Chemistry, Scientific Method and Atoms

These flashcards cover key concepts from the introduction to chemistry, the scientific method, and atomic theory.

Scientific Method

A systematic way of learning that emphasizes observation, experimentation, and reasoning.

Atom

The smallest unit of an element, consisting of a nucleus surrounded by electrons.

Dalton's Atomic Theory

A theory stating that all elements consist of atoms, which are indivisible and vary by mass.

Cathode Ray Tube Experiment

An experiment by J.J. Thomson that led to the discovery of the electron.

Rutherford's Model

An atomic model proposing a small, dense, positively charged nucleus surrounded by electrons.

Bohr's Planetary Theory

A model suggesting electrons orbit the nucleus in fixed paths at specific energy levels.

Radioactivity

The emission of energy or particles from unstable atomic nuclei.

Half-life

The time taken for half of a quantity of a radioactive substance to decay.

Chemical Reaction

A process that involves the transformation of substances into new products.

Isotope

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Aufbau Principle

The principle stating that electrons occupy the lowest energy orbitals available before filling higher ones.

Pauli's Exclusion Principle

A rule that states no two electrons in an atom can have the same set of four quantum numbers.

Hund's Rule

The principle that electrons will fill degenerate orbitals singly before pairing up.

Mass Spectrometer

An instrument used to measure the mass-to-charge ratio of ions.

Chemical Safety Symbol

Visual signs used to indicate the risks associated with chemical substances.

Plum Pudding Model

A model proposed by J.J. Thomson where negatively charged electrons are embedded in a positively charged 'pudding'.

Nuclear Reaction

A process in which the structure of an atomic nucleus changes.

Continuous Spectrum

A spectrum that contains all wavelengths of light without any interruptions.

Line Spectrum

A spectrum showing discrete wavelengths emitted by excited atoms.