Introduction to Chemistry: Scientific Method and Atoms

These flashcards cover key concepts and definitions from the chemistry lecture on the scientific method and atomic theory.

What is the scientific method?

A systematic approach used by scientists to investigate and learn about the natural world.

What is Dalton's atomic theory?

A theory that states all elements are made of small indivisible particles called atoms.

What is J.J. Thomson known for?

He is known for discovering the electron through his cathode ray experiment.

What is Rutherford's gold foil experiment?

An experiment that led to the discovery of the atomic nucleus by observing the deflection of alpha particles through gold foil.

What is Bohr's theory about atomic structure?

Bohr's theory posits that electrons orbit the nucleus in fixed, quantised energy levels.

What is radioactivity?

The process by which unstable atomic nuclei decay, releasing energetic particles or electromagnetic radiation.

What are isotopes?

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

What is meant by the term 'half-life' in radioactivity?

The time required for half of the radioactive atoms in a sample to decay.

What is the difference between a chemical reaction and a nuclear reaction?

A chemical reaction involves electrons and does not change the identity of atoms, while a nuclear reaction involves changes in the atomic nucleus.

What is the Aufbau principle?

The principle stating that electrons fill atomic orbitals in order of increasing energy.

What does the Pauli Exclusion Principle state?

No two electrons in an atom can have the same set of quantum numbers, meaning they must have opposite spins when in the same orbital.

What is Hund's Rule?

Within a subshell, electrons will occupy all degenerate (equal energy) orbitals singly before pairing.

What is the definition of a hypothesis?

A testable explanation or prediction based on prior knowledge used to guide experimentation.

What is the continuous spectrum?

A spectrum that contains radiation of all energies within a certain range, appearing as a smooth gradient.

What type of radiation is alpha radiation?

Consists of two protons and two neutrons, essentially a helium nucleus, and has a +2 charge.

What type of particle is emitted during beta decay?

A beta particle, which is a high-energy electron.

What is a mass spectrometer used for?

An instrument used to measure the mass-to-charge ratio of ions, helping in the analysis of the composition of samples.