Honors Chemistry - Unit 4 Review

Vocabulary practice flashcards covering atomic models, subatomic particle properties, electromagnetic radiation, electron configurations, and nuclear structure from Honors Chemistry Unit 4.

Billiard Ball Model

The atomic model proposed by Dalton which describes the atom as a featureless sphere.

Plum Pudding Model

The atomic model proposed by J.J. Thomson featuring a positive space embedded with mobile negative electrons.

Cathode Ray Tube Experiment

J.J. Thomson's experiment showing that cathode rays are repelled by a negative plate, demonstrating that matter possesses internal negative charge.

Nuclear Model

The atomic model proposed by E. Rutherford depicting a dense, positively charged nucleus surrounded by electrons, with the rest of the atom being mostly empty space.

Gold Foil Experiment

E. Rutherford's experiment directing alpha particles at gold foil; most particles passed straight through (showing atoms are mostly empty space), while some deflected or rebounded (revealing a dense, positive core).

Planetary Model

The atomic model proposed by N. Bohr, based on the hydrogen emission line spectrum, in which electrons orbit the nucleus in specific circular energy levels.

Quantum Mechanical Model

The atomic model formulated by E. Schrödinger that uses mathematical calculations to determine a $90\%$ probability of finding an electron in 3-D regions called orbitals.

Proton

A positively charged subatomic particle ($p^+$) located in the nucleus with a relative charge of $+1$ and a relative mass of $1$.

Neutron

A neutral subatomic particle ($n^0$) located in the nucleus with a relative charge of $0$ and a relative mass of $1$.

Electron

A negatively charged subatomic particle ($e^-$) with a relative charge of $-1$ and a relative mass of $\frac{1}{2000}$; it is mobile, can be gained or lost, and acts as the 'key player' in chemical reactions.

Electrical Conductors

Materials, such as metals, containing mobile electrons that can shift across atoms to position themselves as close as possible to an opposite charge.

Electrical Insulators

Non-metal materials in which electrons remain within the proximity of their individual atoms, only able to 'lean' toward an opposite charge.

Atomic Number

The fundamental characteristic of an atom determined strictly by the number of protons in its nucleus.

Mass Number

The total count of protons and neutrons present within the nucleus of an atom.

Isotopes

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

Wavelength and Frequency Relationship

An inverse relationship ($\lambda \propto \frac{1}{\nu}$) where as wavelength increases, frequency decreases.

Frequency and Energy Relationship

A direct, proportional relationship ($E \propto \nu$) where radiation with higher frequency corresponds to higher energy.

Electromagnetic Radiation Spectrum

The full span of electromagnetic radiation ordered from lowest energy (longest wavelength) to highest energy: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Atomic Emission Spectrum

Discontinuous, discrete lines of light emitted when energized electrons drop from higher energy levels to lower energy levels, releasing specific frequencies of radiation.

Ground State

The lowest, standard energy state occupied by an electron before it absorbs energy.

Excited State

An unstable, higher energy level reached when an electron absorbs energy and jumps away from the nucleus.

Orbital Spin Diagram

A box-and-arrow notation representing electron placement and spin within subshell orbitals to help explain chemical bonding.

Valence Electrons

Electrons located in the highest occupied principal energy level of an atom that determine group reactivity and bonding properties.