Electrons are the smallest subatomic particles with a negative charge.

The atomic number is equal to the number of protons in an atom.

Bohr proposed the planetary model with electrons orbiting the nucleus.

Protons carry a positive charge of +1.

The azimuthal quantum number determines the orbital shape.

The s sublevel can hold a maximum of 2 electrons.

Chadwick discovered the neutron in 1932.

Carbon-14 is used in radiocarbon dating.

The Pauli Exclusion Principle refers to the spin of electrons.

Mass number is the sum of protons and neutrons in an atom.

The p sublevel consists of three orbitals.

Hydrogen is the first element with atomic number 1.

The principal quantum number represents the energy level.

Electrons carry a negative charge of -1.

Neutrons carry no net electric charge.

Electrons have a very small and negligible mass.

The nucleus contains protons and neutrons.

The modern model is based on wave functions and probability.

The third energy level can hold a maximum of 18 electrons.

Potassium has this electron configuration.

Schrödinger contributed to the development of quantum numbers.

The magnetic quantum number specifies orbital orientation.

Half-life is the time for half the substance to decay.

Electrons fill orbitals in order of increasing energy.

Outermost level electrons are called valence electrons.

The f sublevel can hold a maximum of 14 electrons.

Heisenberg proposed the uncertainty principle.

Isotopes have the same number of protons but different neutrons.

S orbitals have a spherical shape.

Titanium has this electron configuration.

The mass of an electron is approximately equal to a positron.

Isobars have the same mass number but different atomic numbers.

Neon is a noble gas in Group 18.

Bohr's model was primarily successful for hydrogen spectra.

The electron cloud model describes the probability of electron location.

Isotopes have the same number of protons but different neutrons.

De Broglie proposed the wave-particle duality of matter.

Wavelength is the distance between wave peaks.

Electrons in the quantum model exhibit wave-like behavior.

The outermost shell is called the valence shell.

An orbital is a region of high probability of finding an electron.

The Uncertainty Principle relates position and momentum.

The d sublevel can hold a maximum of 10 electrons.

The azimuthal quantum number differentiates orbitals within the same energy level.

Silicon has this electron configuration.

Bohr's model was successful for hydrogen's line spectrum.

Ionization involves gaining or losing electrons.

Electronegativity measures electron attraction in a bond.

Schrödinger equation calculates electron wave functions.

The photoelectric effect is the ejection of electrons by light.

Bohr introduced quantized angular momentum in atomic orbits.

Bromine has this electron configuration.

The spin quantum number describes electron spin.

Radioactive decay involves the spontaneous emission of radiation.

Neutrons and protons contribute to an atom's mass.

Isotopes have the same atomic number but different mass.

Quantum numbers describe electron behavior.

An alpha particle is a helium nucleus with 2 protons and 2 neutrons.

Schrödinger developed equations for electron probability distribution.

Ionization energy is the energy needed to remove an electron.

Beta decay emits an electron.

Atomic mass is the weighted average mass of isotopes.

Iron has this electron configuration.

Ground state is the lowest energy state of an atom.

Aufbau principle dictates filling lowest energy orbitals first.

Neutrons contribute to the stability of a nucleus.

The electron cloud represents the probable location of an electron.

A quantum leap involves an electron moving between energy levels.

Bohr introduced the concept of quantized energy levels.

An excited state corresponds to a higher energy level.

Isoelectronic species have the same number of electrons.

Rubidium has this electron configuration.

Ionization energy is needed to remove an electron from a cation.

Electron capture involves the absorption of an electron.

Antimony has this electron configuration.

The spin quantum number can be +1/2 or -1/2.

Radioactive decay involves the spontaneous emission of radiation from an unstable nucleus.

The modern periodic law describes the periodicity of elements based on atomic numbers.

Uranium has atomic number 92.

The d sublevel has a clove-shaped orbital.

The magnetic quantum number l = 2 corresponds to the d sublevel.

Noble gas configuration resembles the nearest noble gas.

Electron configuration describes the arrangement of electrons.

Electron affinity measures the tendency to gain electrons.

Radon has this electron configuration.

Nuclear fission involves the splitting of a large nucleus into smaller fragments.

Isoelectronic atoms have the same number of electrons.

Nuclear binding energy is the energy needed to keep a nucleus intact.

Electrons contribute to the magnetic properties of an atom.

The nuclear shell model is based on the shell structure of nucleons.

Quantum tunneling involves particles passing through a barrier.

Nuclear isomers have the same mass number but different atomic numbers.

Francium has this electron configuration.

Electron shielding reduces the effective nuclear charge felt by outer electrons.

Lanthanides have filled f-orbitals.

Actinium has this electron configuration.

Radioactive half-life is the time for half the atoms in a sample to decay.

The p sublevel is associated with n = 3.

Light is emitted in an emission spectrum during electron transitions.

Quantum entanglement involves correlated states of two electrons.