Radioactive Decay
Beta : only adds/ subtracts from the atomic numbers/ protons.
Alpha : changes both the atomic mass and the atomic number.
Beta (+) : subtracts from the number of protons in the given atom
Beta (-) : adds to the number of protons in the given atom
Capture: absorbs charges
Emission : releases charges
Subtracts 4 from the mass of the isotope
Subtracts 2 from the atomic number of the isotope
Gamma Radiation
Half-Life: an exponential decay of a number by multiplying it by 1/2
Electromagnetic waves with no mass or charge
Nt=activity at time t N0=initial activity at time=0
most penetrating form of radiation
symbol (y)
The half-life of an isotope- calculate how much radioactivity of that isotope will be present after a certain period of time.
This loss of activity can be estimated by determining the half-life of an isotope.
Fusion: when two atoms slam together to form a heavier atom
Fission:when a neutron slams into a larger atom, forcing it to excite and split into two smaller atoms
Electron Configuration
Ionization Energy
Types of electrons
Ionization energy decreases as the size of the atom gets larger (atomic size)
Definition: the amount of energy required to remove an electron from an isolated atom or molecule
The positive charge holds the electrons more tightly and thus removal of electrons becomes more difficult.
Valence Electrons: the electrons orbiting the nucleus in the outermost atomic shell of an atom
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Core Electrons: Electrons that are closer to the nucleus are in filled orbitals
Molecular Geometry
Lewis Diagram
Intermolecular Forces: the force that mediates interaction between molecules
Definition: A simplified representation of the valence shell electrons in a molecule.
- helps visualize the valence electrons of atoms and molecules, whether they exist as lone pairs or within bonds.
Molecular Structure: the three-dimensional structure or arrangement of atoms in a molecule.
Linear: In a linear model, atoms are connected in a straight line.
Trigonal planar: Molecules with the trigonal planar shape are somewhat triangular and in one plane (flat).
Bent: Angular molecules have a non-linear shape
The VSEPR theory describes four main shapes of simple molecules: linear, trigonal planar, tetrahedral, and bent.
London dispersion force: a weak intermolecular force between two atoms or molecules in close proximity to each other.
dipole-dipole interaction: when two dipolar molecules interact with each other through space.
ion-dipole interaction: the result of an electrostatic interaction between a charged ion and a molecule that has a dipole.
Hydrogen Bonding:A strong type of dipole-dipole attraction that one of these of type of bonds- Oxygen, Nitrogen, and Fluorine