Chapter 6 - The Periodic Table and Periodic Law

periodic law

the statement that there is a periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number

groups

(families) series of vertical columns on the periodic table

periods

horizontal rows on the periodic table - (there are seven); the period number indicates the energy level

representative elements

the main group of elements that possess a wide range of chemical and physical properties (1A through 8A)

transition elements

elements labeled 1B through 8B on the periodic table

metals

elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity; malleable and ductile

alkali metals

the group 1A elements (except for hydrogen)

alkaline earth metals

the group 2A elements

transition metals

the group B elements

inner transition metals

elements 58-71 and 90-103 located beneath the periodic table

nonmetals

elements that are generally gases or brittle, dull-looking solids; poor conductors of heat and electricity

halogens

group 7A elements

noble gases

group 8A elements - extremely unreactive

metaliods

elements with physical and chemical properties of both metals and nonmetals

ion

an atom or a bonded group of atoms that has a positive or negative charge

ionization energy

the energy required to move an electron from a gaseous atom

octet rule

an atom loses, gains, or shares electrons to aquire a full set of eight valence electrons

electronegativity

the ability of an atom to attract electrons in a chemical bond

John Newlands

arranged elements by increasing atomic mass which led to his discovery of the law of octaves

Dmitri Mendeleev

used some ideas of Newlands to arrange the elements by increasing atomic mass into columns; this led to the creation of the first periodic table

Henry Moseley

arranged elements by increasing atomic number to create a more clear and correct periodic table

atoms in the same group/column

have the similar chemical properties because they have the same number of valence electrons

s-block elements

elements in groups 1A and 2A, plus hydrogen and helium; the valence electrons of these elements occupy only "s" orbitals

p-block elements

elements in groups 3A-8A

d-block elements

the transition metals

f-block elements

the inner transition metals

trend of atomic radii on the PT

decreases as you move across and increases as you move down

trend of ionic radii on the PT

the positive ions decrease as you move across and the large negative ions also decrease as you move across; it increases as you move down

trend of ionic radii on the PT

increases as you move across and decreases as you move down

trend of electronegativity on the PT

increases as you move across and decreases as you move down