[U4] Chem - Periodic Table

Periodic Law

When elements were arranged in order of INCREASING Atomic Mass, similarities in thier chemical properties appeared at regualr intervals

Mendeleev

Created 1st Periodic table in 1871

“Elements w/ similar properties were GROUPED TOGETHER

Table would be used to predict existance + Properties of elements that would fill five of the spaces

Periodic Table

An arrangement of elements in order of their atomic numbers,.

Elements with similar properites fall in the same COLUMN , OR GROUP

Columns

“GROUPS OR FAMILIES”

Share similar chemical properties

Rows

“PERIODS”

Have a pattern of physical properties

Valence Electrons

Electrons in OUTER MOST energy level, amount of Valence determines how an atom reacts

Octet Rule

Atoms Gain, Lose or share valence to have full outer energy level

Ions

Atoms of an element with different numbers of P+ and E-

GAIN E= Atom becomes NEGATIVE

LOSE E= Atom becomes POSITIVE

Alkali Metals

(Lithium, Sodium, Potassium, Rubidium, Caesium, Fraincium)

PURE STATE, silvery appearance, can cut with knife, HIGHLY REACTIVE, NOT FOUND IN NATURE

VALENCE: 1 v e, makes a +1 ion

Alkaline Earth Metals

(Beryllium, Magnesium, Calcium, Strontium, Barium, Radium)

LESS REACTIVE than Alkali Metals, STILL Too reactive to be found in nature

VALENCE: 2 Valence, makes a +2 ion

Transition Elements

GROUPS: 3-12

Typically METALLIC PROPERTIES

VALENCE: N/A, makes MANY different ions

Halogens

GROUP 17: (Fluorine, Chlorine, Bromine, Iodine, Astatine, Tennessium)

MOST REACTIVE non-metals, react Vigorously w/ most metals to form salts

VALENCE: 7 valence, makes -1 ions

Noble Gasses

GROUP 18: Helium, Neon, Argon, Krypton, Xenon, Radon, Oganeessium)

MOST NON-REACTICE ELEMENTS

Valence: 8 Valence, DO NOT FORM IONS

Lantanides

1st ROW on bottom half of PT (57-70):

Shiny metals, REACTIVITY LIKE ALKALINE EARTH METALS

Actinides

2nd ROW on bottom half of PT (89-102)

Actinides are ALL RADIOACTIVE

Metals

LEFT STAIR-STEP LINE INCLUDING F-BLOC

SHINY/LUSTEROUS

conductors of heat and electricity

Ductile, Malleable

React with acids, Solid @ room temp`

Non-Metals

RIGHT STAIR-STEP LINE

DULL/LACKLUSTER, brittle

DO NOT conduct with heat/electricity

usually GAS/LIQUID @ Room temp

Metalloids

BETWEEN BOTH SIDES OF STAIR-STEP LINE

Properties of BOTH METALS AND NONMETALS

(Boron, Silicon, Germanium, Astatinic, Antimary, Tellurim)