Periodic Table and Chemical Properties

Dmitri Mendeleev

• Father of the Periodic Table, placed in order of increasing atomic weight, predicted unknown elements.

• Discovered the electron and its charge.

• Developed the theory of relativity and its implications.

• Created the first atomic model based on quantum mechanics.

Electron Affinity

• The energy change when an electron is added to a neutral atom to form a positive ion.

• The energy change when an electron is added to a neutral atom to form a negative ion.

• The energy required to remove an electron from a neutral atom.

• The energy change when an atom loses a neutron.

Ion Radii

• Cations are larger than their neutral atoms.

• Anions are smaller than their neutral atoms.

• Cations are smaller than their neutral atoms.

• Ion radii do not follow any trends.

Metals

• Elements that are typically dull, brittle, and poor conductors of heat and electricity.

• Elements that are typically shiny, malleable, ductile, and good conductors of heat and electricity.

• Elements that are gaseous at room temperature and poor conductors of heat and electricity.

• Elements that are found in the middle of the periodic table and are typically non-reactive.

Atomic Number

• The number of neutrons in the nucleus of an atom.

• The number of protons in the nucleus of an atom, which determines the element's identity and its position in the periodic table.

• The total number of electrons in an atom.

• The mass of an atom measured in atomic mass units.

Halogens (Group 17)

• Highly reactive nonmetals that readily gain one electron to form a -1 ion.

• Stable metals that lose two electrons to form a +2 ion.

• Inert gases that do not react under normal conditions.

• Metalloids that can gain or lose electrons depending on the reaction.

Ionization Energy

• The energy required to remove an electron from a gaseous atom or ion.

• The energy required to add an electron to a gaseous atom or ion.

• The energy required to break a bond in a molecule.

• The energy required to ionize a solid metal.

Group (or Family)

• A horizontal row in the periodic table.

• A vertical column in the periodic table. Elements in the same group have similar chemical properties due to having the same number of valence electrons.

• A type of chemical bond between two elements.

• A classification of elements based on their atomic mass.

Alkali Metals (Group 1)

• Metals that are non-reactive and do not lose electrons easily.

• Highly reactive metals that readily lose one electron to form a +1 ion.

• Metals that are found in the center of the periodic table.

• Metals that can form multiple oxidation states.

Period

• A vertical column in the periodic table where elements share similar properties.

• A horizontal row in the periodic table. Elements in the same period have the same number of electron shells.

• A type of chemical bond between atoms.

• A measure of the time it takes for a chemical reaction to occur.