Metals
Metal
an element that is solid at room temperature, a good conductor of heat and electricity, and generally is shiny; most metals are ductile and malleable
Periodic law
States that when the elements are arranged by increasing atomic number, there is a periodic repetition of their chemical and physical properties
Chemical bond
the force that holds two atoms together; may form by the attraction of a positive ion for a negative ion or by the attraction of a positive nucleus for negative electrons
Electron-dot structure
consists of an element’s symbol, representing the atomic nucleus and inner-level electrons, that is surrounded by dots, representing the atom’s valence electrons
Ion
an atom or bonded group of atoms with a positive or negative charge
Alkali metal
group 1 elements, except for hydrogen, that are on the left side of the modern periodic table
Molecule
forms when two or more atoms covalently bond and is lower in potential energy then its constituent atoms
Ionic Bond
the electrostatic force that holds oppositely charged particles together in an ionic compound
Nonmetal
elements that are generally gases or dull, brittle solids that are poor conductors of heat and electricity
Ionization energy
the energy required to remove an electron from a gaseous atom; generally increases in moving from left-to-right across a period and decreases in moving down a group
Alkaline earth metal
group 2 elements in the modern periodic table
Representative element
groups of elements in the modern periodic table that are designated with an A (1A through 8A) and possess a wide range of chemical and physical properties. Also known as the s and p blocks.
Covalent bond
a chemical bond that results from the sharing of valence electrons
Halogen
a highly unreactive group 17 element
Octet rule
states that atoms lose, gain, or share electrons in order to acquire a full set of eight valence electrons (the stable electron configuration of a noble gas)
Transition metal
– a type of element that is contained in the d-block of the modern periodic table and, with some exceptions, is characterized by a filled outermost s orbital of energy level n, and filled or partially filled d orbital of energy levels n - 1
Transition element
groups of elements in the modern periodic table that are designated with a B (1B through 8B) and are further divided into transition metals and inner transition metals. Also known as the d and f blocks.
Electronegativity
indicates the relative ability of an element’s atoms to attract electrons in a chemical bond. Generally increases in moving from left-to-right across a period and decreases in moving down a group. Noble gases do not have electronegativity values.
Noble gas
an extremely unreactive group 18 element (it is unreactive because its out most orbitals are filled so it doesn’t need to react to get more)
Cation/ Anions
an ion that has a positive charge; forms when valence electrons are removed, giving the ion a stable electron configuration/an ion that has a negative charge; forms when valence electrons are added to the outer energy level, giving the ion a stable electron configuration
Inner transition metal
a type of element that is contained in the f-block of the modern periodic table and is characterized by a filled outmost s orbital, and filled or partially filled 4f and 5f orbitals.
Lewis Structure
a model that uses electron-dot structures to show how electrons are arranged in molecules. Pairs of dots or lines represent bonding pairs
Delocalized Electrons
The electrons involved in metallic bonding that are free to move easily from one atom to the next throughout the metal and are not attached to a particular atom.
Metalloid
an element, such as silicon or germanium that has physical and chemical properties of both metals and nonmetals
Electron Sea Model
Proposes that all metal atoms in a metallic solid contribute their valence electrons to form a “sea” of electrons, and can explain properties of metallic solids such as malleability and ability to conduct an electric current.