Post on 21-May-2015
description
The Periodic Table
Families of Elements
What we will learn…
The names of five chemical familiesAlkali metalsAlkaline earth metalsTransition metalsHalogensNoble gases
What we will learn…
The location of the families on the Periodic Table
The Periodic Table
What we will learn…
Mg burning
Cutting Na
What we will learn…
Mg burning
What we will learn…
Cutting Na
What we will learn…
Key vocabulary
Families
Families (definition): groups of elements that have similar chemical properties.
Chemical Properties
Chemical property (definition): characteristic shown by a substance when it reacts with another substance during a chemical reaction and changes in composition forming a new product
reactant(s) product(s)
The Periodic Table
Alkali Metals (Li, Na, K, Rb, Cs, Fr)
Most reactive family of metalsGroup 1: only 1 valence electron
(+1 ion, or cation)
Never found free in natureKept in mineral oil or
inert gas in lab
Alkali Metals (Li, Na, K, Rb, Cs, Fr)
Often form ionic compounds with nonmetalswhite metallic solids soluble in water
Alkali Metals (Li, Na, K, Rb, Cs, Fr)
Very reactive with nonmetals, especially Halogens like chlorine
Very reactive with oxygen (form oxides)
Very reactive with water (hydroxides)
Alkali Metals (Li, Na, K, Rb, Cs, Fr)Hydroxides and oxides formed react with
water to form basic (/alkaline) solutions
2Na + 2H2O 2NaOH + H2
Mythbusters:Alkaline Metal Explosion
Alkali Metals (Li, Na, K, Rb, Cs, Fr)
Metals (but not always ‘typical’ metals*)Good conductors of heat/electricityMalleable and ductileSolid at room temperature
M.P. and B. P. lower than most metals*
All soft (can be cut with a knife) and shiny silver and lighter (less dense) than other metals (Li, Na and K float on water)*
Alkali Earth Metals (Be, Mg, Ca, Sr, Ba, Ra)
2nd most reactive family of metalsGroup 2: only 2 valence electrons
(+2 ion, or cation)
Never found free in nature
Alkali Earth Metals (Be, Mg, Ca, Sr, Ba, Ra)Form ionic compounds with nonmetals
especially with Halogens
React with oxygen (basic oxides)
Most react with water (alkaline hydroxides)
Calcium + water CaF2
Alkali Earth Metals (Be, Mg, Ca, Sr, Ba, Ra)
MetalsSimilar properties to alkali metals
Electrical conductorsMalleable and ductileShiny Silvery white solidsBut harder and more
dense with higher M.P. and B.P. than group 1
Transition Metals
21 (Scandium) through 29 (Copper)
39 (Yttrium) through 47 (Silver)
57 (Lanthanum) through 79 (Gold)
89 (Actinium)
and all higher numbers
Transition Metals
Have special electron rulesCan use two outermost shells to bond with
other elements Can bond with many elements in a variety of
shapes
Range of oxidation states+2 (unless otherwise noted)
Cu +2Cu IV +4
Transition Metals
Properties vary but most …have lower reactivity
Don’t react quickly with H2O or O2
form brightly colored compounds
Transition Metals
Properties vary but most are…Very good conductors of
heat/electricityMalleable and ductile Hard, tough and strongLustrous and shinyHigh M.P. High density
The Halogen Family (F, Cl, Br, I, At)
The Halogen Family (F, Cl, Br, I, At)Most reactive family of nonmetals
Group 17: 7 valence electrons (-1 anion)
Never found free in nature Form diatomic molecules
The Halogen Family (F, Cl, Br, I, At)Form both ionic and covalent bonds
(compounds and molecules)ionic compounds with metals
“salt formers”covalent compounds with nonmetals
Very reactive with group 1 and 2 metalsVery reactive with hydrogen
The Halogen Family (F, Cl, Br, I, At)Nonmetals
Poor conductors of heat & electricityCrumbly and brittle (when solid)Range of states of matter at RT:
solid (I2) liquid (Br2) gas (F2 , Cl2)
M.P. and B. P. are lowCharacteristic colors and odorsToxic or poisonous
The Noble Gases (He, Ne, Ar, Kr, Xe, Rn)Unreactive (stable) family of gases
Group 18: all have full outer shells 2 valence electrons for Helium8 valence electrons for all others
Always found free in natureDo not form compounds
Some Xe compounds have been formed, but they are not very stable
monatomic
The Noble Gases (He, Ne, Ar, Kr, Xe, Rn)Nonmetals
Colorless, odorless, tasteless gases at R.T. (Earth’s atmosphere)
nonflammableVery low B.P. and M.P.
Hydrogen
Hydrogenproperties of both group 1 and 17
typically shown listed with group 1
non-metal lightest element Least dense element diatomic gas (RT) colorless, odorless, and
tasteless highly flammable
Hydrogen “water-former” Hydrogen
Reacts with elements and other substances (at temperatures > RT)Can donate (+1 cation), accept (-1
anion), or share its electron