Essay on Chemistry: Atom and Electronegativity Nonmetal Reactivity

Submitted By PetaBrooks28
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Nonmetals Metals
Unit 4 Study Guide

Alkali Metals
Alkaline Earth Metals
Noble Gases
Transition Metals
Groups to know:

Alkali Metals -most reactive metals

Halogens -most reactive nonmetals

Noble Gases -nonreactive -no electronegativity

-malleable, ductile, high density, lustrous (shiny), conduct heat and electricity well

-Hydrogen is a nonmetal even though it is on the metals side
-brittle if solid, lower densities, dull, insulators

Some Definitions:
Period -horizontal rows; equal the energy level of the valence electrons
Group -vertical columns on the periodic charge; elements in the same groups tend to have similar properties
Ion -charged atom
Cation -positively charged atom; lost electrons; smaller than the neutral atom
Anion -negatively charged atom; gained electrons; larger than the neutral atom
Isotope -atoms of the same element, but different numbers of neutrons
Ionization Energy -amount of energy needed to remove a valence electron; forms a cation
Electronegativity -attraction of an atom in a compound for a nearby electron; forms an anion

Ionization Energy
Nonmetal Reactivity
Atomic Radius
Metal Reactivity
Atomic Radius
Metal Reactivity
Ionization Energy
Nonmetal Reactivity


Atomic Radius:
Anion > Neutral atom > Cation

Fr (francium) is the most reactive metal and has the largest atomic radius
He (helium) has the highest ionization energy
F (fluorine) has the highest electronegativity and is the most reactive of all nonmetals

*Check your notes to know WHY these trends occur! You must k………………………………………………….now this!!!*

Atomic Theory:
John Dalton 1803 – First Modern Atomic Theory -5 Postulates on the atom: 1. Elements are composed of atoms, which are very small, indivisible, indestructible particles. (false) 2. All atoms of the same element are exactly identical. (false – isotopes!) 3. Atoms of different elements have different properties. (true) 4. Atoms combine in small, whole-number ratios to form compounds. (true) 5. Atoms of one element cannot change into an atom of a different element during a chemical reaction. (true)

J. J. Thomson - discovered the electron using cathode ray tubes -proposed “Plum Pudding Model” – electrons move randomly in a positively charged, amorphous cloud

Ernest Rutherford - discovered the nucleus in the Gold Foil Experiment -proposed that the positive