Chapter 2Atoms, Molecules and Ions

What is in an atom?

Name the three subparticles that make up an atom:

1. 2. 3.

Who Discovered Them?

http://www.physlink.com/Education/AskExperts/ae46.cfm

Label the following:

http://www.chemcool.com/referencetables/periodictable.htm

PRACTICE PROBLEMSCalculate the # of protons, electrons, or neutrons for the following elements

Element Protons Electrons Neutrons

Nitrogen ( )

Silver ( )

Copper ( )

Sodium ( )

Mercury ( )

http://www.dayah.com/periodic/

Critical Thinking

1. Of the three subabomic particles, which one gives the identity to the element? WHY? Explain

2. List at least three facts about the Nucleus.

WEBQUEST!!

Today we are going to use the Internet to research the timeline of the discovery of the atom!

Nuclear Stability: Radioactivity

Radioactivity:

Nuclear reactions: Reactions that change in the _______________ _____________ and produce ____________________.

Three kinds of radiation occur: 1. 2. 3.

http://library.thinkquest.org/17940/texts/radioactivity/radioactivity.html

Nuclear Stability

Almost all the atoms you encounter have a ______________ nuclei not ________________.

Radiation in __________________. What makes a nucleus unstable? Let’s see (and

think)…..Review: Nucleus is made up of ____________ and

_______________.Review: Positive charges _________________ each

other.

So why don’t the protons fly apart from the nucleus?

There is a strong force that overcomes the electrical repulsion known as the Strong ________________ force.

The neutron does _______________ experience and electrical repulsion because it has ______________ charge. It does however help in lessening the repulsion of the protons. The neutron is the glue that holds the nucleus together.

Elements between ______________ and ___________( ______________ to ____________) stable nuclei have ________________ number of protons and neutrons.

After _____________ protons the nucleus needs more ________________ to be stable.

After _____________ protons (_________________) no number of neutrons is sufficient to _________________ the nucleus together indefinitely. After #83 ________________.

Types of Decay

Radioactive elements emit different kinds of radiation

They are distinguished by their charge mass and _______________ power.

Charge and penetration power:Alpha (α)

A stream of high alpha particles which is made of 2 _____________ and 2 __________ (identical to the He+2 nucleus) __________________.

Does not have much _____________ power. Travel only a few _____________ and may

be stopped by paper or clothing

Charge and penetration power: Beta (β)

A stream of high speed ___________ . NOT the electrons that come from the orbital of the atom, the electron must come from the NUCLEUS.

A NEUTRON CHANGES INTO A ________________ (which remains in the nucleus) AND AN ___________.

The beta particle (or electron) is propelled out of the nucleus at _____________ speed.

Beta radiation is about 100 times more penetrating than alpha radiation. It can penetrate 1-2 millimeters into solid material.

MAY pass through ___________ and damage skin.

Charge and penetration power: Gamma (γ)

A very energetic form of light that our eyes ____________ see.

Does not consist of particles. Sybolized: It is able to penetrate deeply into a solid

material, including body tissue. VERY DANGEROUS.

Nuclear reactions

Nuclear reactions: A reaction that keeps track of reactant’s components.

Alpha

Beta

The Molecule

Different Formulas: Molecular:

Empirical:

Structural

http://dbhs.wvusd.k12.ca.us/webdocs/Mole/EmpiricalFormula.html

http://dl.clackamas.edu/ch106-01/strform.htm

The ION

Cation:

Anion:

http://www.launc.tased.edu.au/online/sciences/PhysSci/pschem/ion/Ions.htm

http://www.launc.tased.edu.au/online/sciences/PhysSci/pschem/ion/Cations.htm

http://www.launc.tased.edu.au/online/sciences/PhysSci/pschem/ion/Anions.htm

Examples

Indicate the number of protons, neutrons and electrons for the following:

1. Sodium atom Sodium ion

Example 2

2. Chlorine atom Chlorine ion

Try These!

Ion #of Protons

# of Electrons

# of neutrons

O-2

Al+3

F-1

Pb+2

N-3

Isotopes

H1 (hydrogen): ________p, ________e, ________n (99.9844%)

H2 (deutrerium):________p, ________e, ________n ( .0156%)

H3 (tritium): _________p, ________e, ________n (0.0004%)

http://www.colorado.edu/physics/2000/isotopes/

http://www.dayah.com/periodic/

About The Periodic Table:Define These

Family/Group:

Period:

Main group elements

Characteristics of the periodic table:

CharacteristicsMetals Non-Metals

1. 1.

2. 2.

3. 3.

4. 4.

http://chemistry.about.com/od/elementgroups/a/nonmetals.htm

http://chemistry.about.com/od/elementgroups/a/metals.htm

Characteristics

Semi-Metals:

http://chemistry.about.com/od/elementgroups/a/metalloids.htm

Writing Compounds

First: What are the charges of each family on the periodic table?

Criss-Cross Method

For Ionic Compounds ONLY!!

Names of compounds

. Monatomic cations: Take the name of the ______________ from which they are derived,

a. Na+ __________________ K+ ____________________

EXCEPT: Many _____________________ metals can form more than one type of cation. A ___________________________ is added to tell the difference.

a. Fe 2+ _________________ Fe 3+ __________________

Monatomic anions

Add the suffix _________ to the end of the stem from which they are derived.

a. N 3- _______________________

b. O 2- ____________________

c. S 2-___________________ (pg.43)

Polyatomic Ions

MEMORIZE THESE!NH4

+= NO3-= CO3

-2= SO4-2=

CH3COO-= BrO3-= CrO4

-2= PO4-3=

OH-= ClO3-= C2O4

-2= OCl-=

REVIEW

Ionic Compounds: (REVIEW: Ions are made up of a ______________ and a __________________.) First name the _____________________ then the ____________________.

Binary Molecular Coupounds: (REVIEW: Molecules are made up of a ______________ and a __________________.)

Diatomic molecules

Diatomic molecules :

What are the diatomic molecules?

Rules for Naming molecules

Rules are the same as ionic compounds however, now include prefixes Mono is only for second element!!!

2.Prefixes:1= 6=2= 7=3= 8=4= 9=5= 10=

Mono is only for second element!!!

http://www.chemistry.ohio-state.edu/~woodward/ch121/ch2_naming.htm

Examples

N2O3=

NF3=

PCl5=

P2O5=

O2=

CO2=

http://www.chem4kids.com/files/atom_naming.html

Flow Chart

If you are a visual person, this might make naming compounds easier:

http://dbhs.wvusd.k12.ca.us/webdocs/Nomenclature/HO6-Flowchart-Naming.pdf

Common names of molecules: Memorize these!

H2O Water PH3 Phosphine

H2O2 Hydrogen peroxide

AsH3 Arsine

NH3 Ammonia NO Nitric oxide

N2H4 Hydrazine N2O Nitrous oxide

C2H2 Acetylene CH4 Methane

Naming Acids

HCl (g) H+ (aq) Cl- (aq)

HBr (g) H+ (aq) Br-(aq)

HI (g) H+ (aq) I- (aq)

Certain binary molecular compounds that start with ________ form acids when combined with ____________.

http://antoine.frostburg.edu/chem/senese/101/compounds/slides/sld009.htm

Review With These:

http://www.cottonchemistry.bizland.com/chapter9/Chapter%209%20Chemical%20Names%20and%20Formulas.ppt