Atomic Structure Practice Flashcards

This set of vocabulary flashcards covers the foundational concepts of atomic structure, historical models, subatomic particles, periodic trends, and mass spectrometry based on the Chapter 1 lecture notes.

Atom

The smallest part of an element that can take part in a chemical change.

John Dalton

The scientist who proposed the first comprehensive scientific theory about the atom in 1803.

Rutherford scattering experiment

An experiment that led to the discovery of the accepted model of the atom: a small, dense central nucleus surrounded by orbiting electrons in shells.

Bohr model

A model postulating that electrons move in orbits with fixed space and energy, where energy increases as electrons move further from the nucleus.

Quantum Mechanical Model

An improved atomic model created by Shrődinger that treats electrons as waves applying wave function equations.

Nucleons

A collective term for protons and neutrons because they are found in the nucleus.

Proton ($p^+$)

A subatomic particle in the nucleus with a relative mass of $1$, a relative charge of $+1$, and a charge of $+1.60 \times 10^{-19}$ C.

Neutron ($n^0$)

A subatomic particle in the nucleus with a relative mass of $1$ and a relative charge of $0$.

Electron ($e^-$)

A subatomic particle found around the nucleus with a relative mass of $\frac{1}{1840}$ and a relative charge of $-1$.

Valence electrons

The electrons furthest from the nucleus and most loosely held, involved in the formation of chemical bonds.

Strong nuclear force

The force that holds protons and neutrons together in the nucleus, which is stronger than the electrostatic force of attraction.

Atomic number ($Z$)

The number of protons in the nucleus of an atom, also known as the proton number.

Mass number

The total number of protons and neutrons in the nucleus of an atom.

Ion

A charged particle formed when an atom gains or loses an electron.

Cation

A positively charged ion formed when an atom loses an electron (e.g., $Na^+$, $Mg^{2+}$).

Anion

A negatively charged ion formed when an atom gains an electron (e.g., $Cl^-$, $O^{2-}$).

Atomic Radius

Measure of the size of an atom, defined as half the distance between the two nuclei of two covalently bonded atoms of the same type.

Shielding

A process where electrons in the inner shells repel electrons in the outermost shells, weakening the pull of the nuclei on the electrons.

Ionic Radius

A measure of the size of an ion; it increases with increasing negative charge and decreases with increasing positive charge.

Nuclear charge

The positive charge present in the nucleus of an atom, which is equal to the number of protons.

Relative Atomic Mass ($A_r$)

The mean mass of an atom of an element relative to one-twelfth of the mean mass of an atom of the carbon-12 isotope.

Isotopes

Atoms of the same element which have the same atomic number but different mass numbers due to a different number of neutrons.

Mass Spectrometry

An analytical technique used for accurate determination of relative atomic mass and relative molecular mass based on isotopic abundances.

TOF-Spectrometry

Time of Flight Spectrometry, consisting of four stages: Ionization, Acceleration, Ion Drift, and Detection.

Molecular ion peak ($M^+$)

The final peak in a mass spectrum representing the highest $m/z$ value, which indicates the molecular mass of an organic molecule.