Atomic Atomic Structure Structure Chapter 4 Chapter 4
Atomic Atomic StructureStructure
Chapter 4Chapter 4
The AtomThe Atom
The smallest particle of an The smallest particle of an element that retains its identity in element that retains its identity in a chemical reactiona chemical reaction
A penny is about 200,000,000 A penny is about 200,000,000 copper atoms acrosscopper atoms across
Just How Small Is an Atom?Just How Small Is an Atom? Remember looking at these last Remember looking at these last
year?year? You would have to magnify them a You would have to magnify them a
billion times more to see the atoms billion times more to see the atoms they are made of.(1,000,000,000x)they are made of.(1,000,000,000x)
The AtomThe Atom There are three kinds of particles There are three kinds of particles
that make up atoms.that make up atoms. These are called subatomic These are called subatomic
particles.particles.
Protons & NeutronsProtons & Neutrons
Proton (pProton (p++) is positively charged) is positively charged Neutron (nNeutron (n00) has no charge) has no charge Both have the same mass Both have the same mass
(1.67 x 10(1.67 x 10-24-24g or 1 amu)g or 1 amu)
ElectronsElectrons
Electron (eElectron (e--) is negatively charged) is negatively charged Much less mass than protons or Much less mass than protons or
neutrons (about 2000x less or 0 amu)neutrons (about 2000x less or 0 amu) Are the cause for Are the cause for allall of an element’s or of an element’s or
compound’s behaviorcompound’s behavior
ArrangementArrangement At the center of an atom is the nucleus. At the center of an atom is the nucleus.
Here are the atom’s protons and neutrons. Here are the atom’s protons and neutrons. Almost all of the atom’s mass.Almost all of the atom’s mass.
Electrons are spread outside of and Electrons are spread outside of and around the nucleus. They produce almost around the nucleus. They produce almost all of an atom’s volume (size)all of an atom’s volume (size)
How Do You Tell Them How Do You Tell Them Apart?Apart?
Elements are different because Elements are different because they have different #’s of they have different #’s of protons.protons.
The # of protons is also an The # of protons is also an element’s element’s Atomic NumberAtomic Number..
Mass NumberMass Number
The sum of the protons and the neutrons The sum of the protons and the neutrons in an atom.in an atom.
Can be used to find the number of Can be used to find the number of neutrons an atom has.neutrons an atom has.
(Mass #) = (# of neutrons) + (Atomic #)(Mass #) = (# of neutrons) + (Atomic #)
IsotopesIsotopes
Atoms that have the same number Atoms that have the same number of protons (they have to) and of protons (they have to) and electrons, but different numbers of electrons, but different numbers of neutrons.neutrons.
When atoms begin to have more When atoms begin to have more than enough neutrons, they become than enough neutrons, they become unstable. This is radioactivity.unstable. This is radioactivity.
Starting on p. 91-102Starting on p. 91-102 What year or time period…What year or time period… What country the person was What country the person was
from or where they did their from or where they did their work….work….
What their contribution or What their contribution or discovery was….discovery was….
Why it’s significant……Why it’s significant……
DemocritusDemocritus
John DaltonJohn Dalton
Michael FaradayMichael Faraday
Benjamin FranklinBenjamin Franklin
J.J. ThomsonJ.J. Thomson
Robert MillikanRobert Millikan
Henri BecquerelHenri Becquerel
Pierre and Marie CuriePierre and Marie Curie
Ernest RutherfordErnest Rutherford
Are These the Only Are These the Only People?People?NO !!!NO !!! James Chadwick-discovers the neutron in 1932James Chadwick-discovers the neutron in 1932 Neils Bohr-a GIANT in the field of scienceNeils Bohr-a GIANT in the field of science Albert Einstein-perhaps you’ve heard of himAlbert Einstein-perhaps you’ve heard of him Werner Heisenberg-quantum theoryWerner Heisenberg-quantum theory Joseph PriestleyJoseph Priestley ……and many moreand many more
1 2 3 4
5 6 7 8
Ions (charged particles)Ions (charged particles) Monatomic (1 atom) ions have Monatomic (1 atom) ions have
different numbers of protons and different numbers of protons and electrons.electrons.
An atom has no charge because An atom has no charge because (# of p (# of p++) = (# of e) = (# of e--))
An ion has a charge because there An ion has a charge because there is a charge imbalance is a charge imbalance (# of p(# of p++) ) ≠ (# of e≠ (# of e--))
Charge = (# of pCharge = (# of p++) – (# of e) – (# of e--))
Ions (charged particles)Ions (charged particles) Monatomic (1 atom) ions Monatomic (1 atom) ions have different have different
numbers of protons and electrons. For numbers of protons and electrons. For example: Hexample: H++, Cl, Cl--, Na, Na++, O, O2-2-..
Polyatomic ions (more than 1 atom) Polyatomic ions (more than 1 atom) are small molecules that possess an are small molecules that possess an excess of electrons, so they have a excess of electrons, so they have a charge. For example: NHcharge. For example: NH44
++, PO, PO443-3-, SO, SO44
2-2-, ,
OHOH--..
Ionic CompoundsIonic Compounds Formed from the combining of ions.Formed from the combining of ions. ALWAYS a metal bonded to a non-ALWAYS a metal bonded to a non-
metal.metal. Positive ion is a Positive ion is a cationcation.. Negative ion is an Negative ion is an anionanion.. We will be working with BINARY We will be working with BINARY
compounds (two parts).compounds (two parts).
Naming Ionic CompoundsNaming Ionic Compounds
Cation is always written first.Cation is always written first. Identify the cation and name it.Identify the cation and name it. Identify the anion and name it.Identify the anion and name it.
Formulas of Ionic Formulas of Ionic CompoundsCompounds
Identify the cation and the anion.Identify the cation and the anion. Balance the charges. You need equal Balance the charges. You need equal
amounts of + and – charge. (Criss-cross)amounts of + and – charge. (Criss-cross) Write the formula, with a subscript for Write the formula, with a subscript for
any ion that there is 2 or more of.any ion that there is 2 or more of. If you use 2 or more of a polyatomic ion, If you use 2 or more of a polyatomic ion,
it needs parentheses.it needs parentheses.
Matter
Pure Substances Mixtures
Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures
Ionic CompoundsMetals
Non-Metals
Matter
Pure Substances Mixtures
Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures
Ionic Compounds
Hydrates
Metals
Non-Metals
HydratesHydrates
Ionic compounds with water Ionic compounds with water trapped in the crystal structure.trapped in the crystal structure.
Naming HydratesNaming Hydrates
Name the ionic part of the Name the ionic part of the compound first.compound first.
Then name the hydrate part with Then name the hydrate part with a prefix and the word “hydrate”.a prefix and the word “hydrate”.
What are the prefixes????What are the prefixes????
PrefixesPrefixes 1------mono1------mono 2------di2------di 3------tri3------tri 4------tetra4------tetra 5------penta5------penta 6------hexa6------hexa 7------hepta7------hepta 8------octa8------octa 9------nona9------nona 10----deca10----deca
Matter
Pure Substances Mixtures
Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures
Ionic Compounds
Hydrates
Metals
Non-Metals
Matter
Pure Substances Mixtures
Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures
Ionic Compounds
Hydrates
Covalent Compounds
Metals
Non-Metals
Covalent CompoundsCovalent Compounds
ALWAYS a nonmetal bonded to ALWAYS a nonmetal bonded to a nonmetala nonmetal
Not bonded due to opposite Not bonded due to opposite electrical charges (like ionic electrical charges (like ionic compounds are)compounds are)
Naming Covalent Naming Covalent CompoundsCompounds
Name the cation as an Name the cation as an elementelement.. Add a prefix to the cation if there Add a prefix to the cation if there
are two or more.are two or more. Name anion as an Name anion as an ionion Add a prefix to the anion no Add a prefix to the anion no
matter how many there are.matter how many there are.
Formulas for MoleculesFormulas for Molecules
The prefix in each part of the The prefix in each part of the name tells you how many of name tells you how many of component there are/is.component there are/is.
Matter
Pure Substances Mixtures
Elements Compounds Homogeneous Mixtures Heterogeneous Mixtures
Ionic Compounds
Hydrates
Covalent Compounds
Acids
Metals
Non-Metals
AcidsAcids The cation for an acid is ALWAYS hydrogen.The cation for an acid is ALWAYS hydrogen. The names for acids come from the anion in the The names for acids come from the anion in the
acid.acid. The names for acids are as shown:The names for acids are as shown:
HCl-Hydrochloric AcidHCl-Hydrochloric Acid HNOHNO33-Nitric Acid-Nitric Acid
HH22SOSO44-Sulfuric Acid-Sulfuric Acid
HH33POPO44-Phosphoric Acid-Phosphoric Acid
HCHHCH33COO-Acetic AcidCOO-Acetic Acid
1st Element Listed
Metal Hydrogen Nonmetal
Ionic-no prefixes Acid-memorized Molecular-prefixes