Historical Development
Idea which states that the physical and chemical properties of the elements are periodic functions of their atomic numbers
periodic law
A row of the periodic table
period
Term for the number of atoms with which an element may combine
valence
"salt-former"
halogens
Dobereiner identified groups of three elements with similar properties which he called this
triads
Another name for metalloids
semimetals
The group of metals that exist in compounds as 1+ ions
alkali metals
Elements in the same column
group
He developed the periodic table of elements
Dimitri Mendeleev
always found in nature as 2+ ions
alkaline earth metals
Elements in the same group will have similar _____
valences
The periodic trend for decreasing atomic radius
up and to the right
By this property is the modern periodic table organized
atomic number
Groups 3-12
transition metals
Highly reactive soft solids with low melting points
alkali metals
The ability of chemically combined atoms to attract electrons to themselves
electronegativity
The idea that orbitals fill in order of increasing n + 1 and that orbitals with the same n + 1 fill in order of increasing n
Madelung rule
Do not readily combine with other elements
noble gases
The effect in which electrons in lower shells block part of the attractive force of the nucleus from reaching electrons in higher shells
electron shielding
The energy released when one electron is added to a gaseous atom of an element
electron affinity