Unit 3 Flashcards
Valence Electrons
Electrons that are found in an atom’s outermost energy level (furthest from the nucleus) these are important because they determine how an atom will bond and react
The Octet Rule
All elements are trying to become stable by achieving a full valence shell of electrons
- Each elecment wants to be as stable as possible by obtaining a full valence shell
- Most of the elements want to have 8 valence electrons
- Atoms will form an ion (atom with a charge) based on the easiest way to obtain a full shell
Group
Also called a family
VERTICAL columns on the periodic table
Elements in the same group have the same number of valence electrons and similar properties
Period
HORIZONTAL rows of the periodic table
Have the same number of energy levels
What are the 3 main element classifications?
Metal
Non-metal
Metalliods
Metals
Examples: Sodium, Calcium, Gold Common properties: -Shiny -Usually grey -High melting/boiling points, mostly solid at room temp. -Good conductors of heat and electricity -Reacts with acid to form hydrogen gas
Nonmetals
Examples: Argon, Chlorine, Neon
Common properties:
-Mostly dull looking
-Most are solid, but some liquids and even gases at room temp
-Not good conductors of heat and electricity
-Low melting/boiling points
Metalloids
Examples: Boron, Silicon, Antinomy
Common properties:
Have some properties in common with metals and some with nonmetals
Group 1
Alklai Metals
Lithium, Sodium, Potassium, Rubidium, Cesium, Francium
-Does NOT include hydrogen
-soft metals-usually exist in compounds
-highly reactive-react voilently with water
valence electrons: 1
Ion formed: +1
Group 2
Alklai Earth Metals
Beryllium, Magnesium, Calcium, Strontium, Barium, Radium
-reactive metals (slightly less reactive than Group 1 since they have to lose 2 valence electrons)
-Minerals-important in the body
valence electrons: 2
Ions formed: +2
Group 13
Boron family
Examples: Boron, Aluminum, Gallium, Indium, Thallium
-aluminum is the most abundant metal and will form a +3 ion
valence electrons: 3
Ions formed: +3
Group 14
Carbon family Carbon, Silicon, Germanium, Tin, Lead -Carbon is the base for life (organic compounds) -Silicon is used in computer chips number of valence electrons: 4 Ion formed: +/- 4
Group 15
Nitrogen family
Nitrogen, Phosphorus, Arsenic, Antimony, Bismuth
-2 nonmetals (Nitrogen and Phophorus) 2 metalloids (Arsenic and Antimony) and 1 metal (Bismuth)
Number of valence electrons: 5
Ions formed: -3 ion
Group 16
Oxygen family
Oxygen, Sulfur, Selenium, Tellurium, Polonium
-3 nonmetals (Oxygen, Sulfur, Selenium), 1 metalloid (Tellurium) and and 1 metal (Polonium)
Number of valence electrons: 6
Ions formed: -2
Group 17
Halogens Flourine, Chlorine, Bromine, Iodine, Astatine, -Most reactive group of nonmetals -Found in nature as diatomic element I Bring Clay From Our New House -Readily combine with metals to form salt (NaCl) Number of valence electrons: 7 Ion formed: -1
Group 18
Noble Gases Helium, Neon, Krypton, Xenon -gases -non reactive (8 valence electrons) -Helium has 2 valence electrons on outershell Number of valence electrons: 8 Ions formed: X
Group 3-12
Transition Metals
- When they form ions, they become more complicated because they have multiple energy levels involved, therefore produce variable charges
- Also includes metals under the staircase
Two groups at the bottom of the periodic table are known as ____
Rare Earth Metals
Period trends
The pattern for a horizontal row on the periodic table (left to right)
Group trend
The pattern for a vertical column on the periodic table (up and down)
Atomic radius
The measure of the size of an atom
measured from the nucleus to the outermost electrons
Period trend for atomic radius
As you move across a period (left to right) atomic radius decreases