Chapter 2 Key Terms Flashcards
(22 cards)
Alpha Particle
A 4/2 He nucleus is emitted from the nucleus during radioactive decay (small positively charged particles).
Anion
Negatively charged ion
Atomic number
Number of protons in the nucleus of an atom.
Cation
Positively charged ion
Electron
Negatively charged particle
Electronic Configuration
Arrangement of electrons in energy levels within an atom.
Emission Spectrum
Set of coloured lines on a black background obtained when light (emitted by excited electrons as they move to a lower energy state) is passed through a prism in a spectroscope.
Excited state
When one or more electrons have absorbed energy and are not in their lowest energy levels.
Ground state
When electrons are in their lowest possible energy level.
Ion
Positively or negatively charged atom or group of atoms.
Ionisation energy
Minimum amount of energy required to remove an electron from an atom or ion, in the gaseous state.
Isotope
Atoms with the same atomic number but different mass number (variations of that element)
Mass number
Number of protons and neutrons in the nucleus of an atom.
Nuetron
Particle with no charge
Nucleus
Very small, dense centre of an atom, composed of protons and neutrons.
Orbit
Pat that an electron was through to take as it moved around the nucleus.
Orbital
Regions of space in which electrons move.
Pauli exclusion principle
Principle that states an atomic orbital can hold 0, 1 or 2 electrons.
Proton
Positively charged particle located in the nucleus of an atom.
Quantum mechanics
Branch of science that deals with discrete, indivisible units of energy called quanta.
Shell
Region in which a group of electrons of similar energies move around the nucleus.
Subshell
A subdivision of electron shells separated by electron orbitals.
