Unit 1: Atomic Structure and Properties Flashcards
Symbol
One or two letters that represent an element
Atomic Number
The same as the number of protons in an atom (and electrons when neutrally charged)
Molar Mass
Average mass of a mol of atoms in grams or a single atom in amus
Alkali Metals
Group 1
Alkaline Earth Metals
Group 2
Transition Metals
Groups 3-12
Halogens
Group 17
Noble Gases
Group 18
Lanthanides
Top row underneath the table
Actinides
Bottom row underneath the table
Periods
Horizontal rows of the periodic table
Groups
Vertical columns of the periodic table
Mass Number
Sum of its neutrons and protons
Isotopes
Atoms of an element with different numbers of neutrons
Avogadro’s Number
The number of atoms that are in a single mole of any given element
STP
Standard temperature and pressure
0 C and 1 atm
Molarity (M)
The concentration of a solution in terms of volume
Percent Composition
The percent by mass of each element that makes up a compound
Empirical Formula
The simplest ratio of one element to another in a compound
Molecular Formula
The actual formula for a substance
Quantized
Electrons can exist only at specific energy levels, separated by specific intervals
Coulomb’s Law
Electrostatic force between the nucleus and an electron = magnitude of the positive/negative charges divided by the distance between the charges
Electromagnetic Radiation
Energy absorbed and emitted by electrons (gamma rays to radio waves)
Ionization (Binding) Energy
The amount of energy necessary to remove an electron from an atom
Kinetic Energy
Energy of motion
Photoelectron Spectrum
Chart of the amount of ionization energy for all electrons ejected from a nucleus
Subshell
The shape of the space the electron can be found in
Energy Level
Distance of the subshell from the nucleus
Aufbau Principle
When building up the electron configuration of an atom, electrons are placed in orbitals, subshells, and shells in order of increasing energy
Pauli Exclusion Principle
The two electrons which share an orbital cannot have the same spin
Hund’s Rule
When an electron is added to a subshell, it will always occupy an empty orbital if one is available
Valence Eletrons
Outermost electrons
Ion
Atom that has either gained or lost electrons
Anion
Negatively charged ion (gained electrons)
Cation
Positively charged ion (lost electrons)
Atomic Radius
Approximated distance from the nucleus of an atom to its valence electrons
Ionization Energy
Energy required to remove an electron from an atom
Electronegativity
How strongly the nucleus of an atom attracts the electrons of other atoms in a bond
Electron Affinity
The energy change that occurs when an electron is added to an atom in its gaseous state
