2.2 The Periodic Table. The Periodic Table Every block represents an element Every periodic table...
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Transcript of 2.2 The Periodic Table. The Periodic Table Every block represents an element Every periodic table...
2.2 The Periodic Table2.2 The Periodic Table
The Periodic TableThe Periodic Table
Every block represents an elementEvery block represents an element
Every periodic table has a keyEvery periodic table has a key
The Periodic TableThe Periodic Table
Where did the modern periodic table come Where did the modern periodic table come from?from? NewlandsNewlands MendeleyevMendeleyev
Modern Periodic TableModern Periodic Table
Period or SeriesPeriod or Series – a horizontal row of – a horizontal row of elements, numbered 1-7)elements, numbered 1-7)
Group or FamilyGroup or Family – a vertical row of – a vertical row of elements (numbered 1-18 on the modern elements (numbered 1-18 on the modern table) (long ago: roman numerals)table) (long ago: roman numerals)
Modern Periodic TableModern Periodic Table
StaircaseStaircase – divides the metals from the – divides the metals from the nonmetalsnonmetals
MetalloidsMetalloids – look like metals but act like – look like metals but act like nonmetalsnonmetals
The Periodic LawThe Periodic Law
States that when elements are arranged in States that when elements are arranged in order of increasing atomic mass, certain order of increasing atomic mass, certain physical and chemical characteristics physical and chemical characteristics repeat in a regular pattern (periodically)repeat in a regular pattern (periodically)
Modern Periodic TableModern Periodic Table
Atomic MassAtomic Mass – defined relative to the – defined relative to the mass of a carbon atom, which is given a mass of a carbon atom, which is given a mass of 12 amumass of 12 amu
AMUAMU (atomic mass unit) – defined as 1/12 (atomic mass unit) – defined as 1/12 the mass of a carbon atomthe mass of a carbon atom
Period / Group NamesPeriod / Group Names
Group 1 – Alkali MetalsGroup 1 – Alkali Metals Soft, silver colored metals that react violently Soft, silver colored metals that react violently
with waterwith water React with the halogensReact with the halogens
Group 2 – Alkaline Earth MetalsGroup 2 – Alkaline Earth Metals Light, reactive metals that form oxide coatings Light, reactive metals that form oxide coatings
with air exposure (ex MgO, CaO)with air exposure (ex MgO, CaO)
Period / Group NamesPeriod / Group Names
Group 17 – HalogensGroup 17 – Halogens Extremely reactive (F is the most)Extremely reactive (F is the most) Form hydrogen halides (ex HCl)Form hydrogen halides (ex HCl)
Group 18 – Noble GasesGroup 18 – Noble Gases Extremely low chemical reactivityExtremely low chemical reactivity
Period / Group NamesPeriod / Group Names
Transition ElementsTransition Elements Groups 3-12Groups 3-12
Representative ElementsRepresentative Elements Groups 1-2, & 13-18Groups 1-2, & 13-18
* Hydrogen is the exception to almost every * Hydrogen is the exception to almost every rule in chemistryrule in chemistry
The AtomThe Atom
The AtomThe Atom
Is the smallest part of an element that is Is the smallest part of an element that is still representative of that elementstill representative of that element
A neutral particle composed of a nucleus A neutral particle composed of a nucleus (containing protons and neutrons) and (containing protons and neutrons) and electronselectrons
# electrons = # protons# electrons = # protons
ElectronsElectrons
ee--
A small, negatively charged subatomic A small, negatively charged subatomic particleparticle
Has negligible massHas negligible mass
NucleusNucleus
The centre of an atomThe centre of an atom
Contains most of the mass and all of the Contains most of the mass and all of the positive charge of an atompositive charge of an atom
ProtonsProtons
pp++
Positively charged subatomic particlePositively charged subatomic particle
Found in the nucleusFound in the nucleus
Mass of 1 amuMass of 1 amu
NeutronsNeutrons
nn
Uncharged (neutral)Uncharged (neutral)
Found in the nucleusFound in the nucleus
Mass of 1 amuMass of 1 amu
Atomic Number and Atomic MassAtomic Number and Atomic Mass
Atomic NumberAtomic Number The number of protons an atom hasThe number of protons an atom has Different for each elementDifferent for each element
Atomic Mass (Mass Number)Atomic Mass (Mass Number) # protons + # neutrons# protons + # neutrons