Chemistry: Periodic Law

periodic law
when elements are arranged in order of increasing atomic number, elements with similar properties appear at regular intervals.
periodic table
the arrangement of elements in order of their atomic number so that elements with similar properties fall in the same column or group
groups or families
18 vertical columns on the periodic table. Elements in the same group have similar physical and chemical properties.
7 horizontal rows; elements in the same period have different physical and chemical properties.
What are the 4 sublevel blocks of the periodic table?
Group 1
What group does Alkali metals belong in? They are highly reactive, silver, soft, never found free in nature, reacts violently with water, stored in kerosene, low melting points, and low density.
Group 2
What group does Alkaline metals belong to? They are harder, denser, strong than alkalies, have higher melting points, less reactive but too reactive to be found in nature.
s block elements
what block contains group 1-2?
d block elements
what block contains group 3-12?
They are called transition elements. all metals, good conductors of electricity, high luster, less reactive than groups 1+2.
p block elements
what block contains group 13-18?
most reactive nonmetals
mostly brittle solids that have properties of both metals and nonmetals
sandwiched between groups 3 and 4 in the 6th period; includes elements 57-71; shiny metals similar in reaction to the alkalines.
sandwiched between groups 3 and 4 in the 7th period. includes elements 89-103; all are radioactive; 1st 4 found on earth, the remainder produced in laboratories.
atomic radius
1/2 of the distance between the nuclei of identical atoms that are bonded together.
ionization energy
the amount of energy needed to remove one electron from a neutral atom
an atom or group of atoms that has a positive or negative charge
any process that results in the formation of an ion
electron affinity
the energy that is associated with adding an electron to an atom.
ionic energy
how the radii of an ion compares to the overall size of the parent atom before gaining or losing an electron
positive ion; formed by losing an electron; metals
negative ion; formed by gaining an electron; nonmetals
a measure of the ability of an atom in a chemical compound to attract electrons
valence electrons
the electrons available to be gained, lost, or shared in the formation of a chemical compound.