November 24,25 and 26
mole
the amount of a substance that contains 6.02 x 10 exp23 representative particles of that substance. The mass is equal to its' atomic mass in grams of the substance.
Representative particle
the particle that a substance commonly exists in. Example: atoms, molecules, ions
Avogadro's number
6.02 x 10 exp 23
the number of representative particles contained in one mole of a substance.
molar mass
the mass of one mole of a substance . Equal to the atomic mass ( or sum of atomic masses)of the substance in grams.
November 14 to 21
Types of Chemical Reactions
Synthesis (Combination) Reaction
A reaction in which two or more substances react to produce a single product.
A + B ----> AB
decomposition reaction
A reaction in which a single compound breaks down into two or more elements or compounds.
AB ------> A + B
Single-Replacement Reactions
A reaction in which the atoms of one element replace the atoms of another element in a compound
A + BX ------> AX + B
or
A + XB -------> XA + B
A metal or halogen will only replace another metal or halogen if it is more reactive than that metal or halogen. You must refer to the activity series of metals or halogens.
Double Replacement Reactions
A reaction that involves the exchange of ions between two compounds
AB + CD -----> AD + CB
Combustion Reactions
A reaction in which oxygen combines with a substance.
A + O2 -------->
November 12 and 13, 2014
In a balanced chemical equation the mass is conserved.
Each side of the equation has the same number of atoms of each element.
November 10 and 11, 2014
Chemical reaction
The changing of substances into different substances by the breaking of old bonds and the formation of new bonds
Chemical equation
An expression representing a chemical reaction. (a recipe)
The formulas of the reactants(on the left) are connected by an arrow with the formulas of the
products on the
right.
Reactant
A starting substance in
a chemical reaction
Product
A substance formed in a chemical reaction
Coefficient
A small whole number
that appears in front of a formula that indicated the number of molecules, atoms or formula units, of that substance
Subscript
a number that appears smaller than the normal type and slightly below to indicate the number
of that element in the
compound
In a balanced chemical equation the mass is conserved.
Each side of the equation has the same number of atoms of each element.
atom
single unit of an element (except for the diatomics)
molecule
single unit of a compound or diatomic element
formula unit
single unit of an ionic
compound
mole
the amount of a substance that contains 6.02 x 10 ^23 representative particles of that
substance. The mass is equal to its' atomic mass in grams of the
substance.
Representative particle
the particle that a substance commonly exists in.
Example: atoms, molecules,
ions
Avogadro's number
6.02 x 10 ^ 23
the number of representative particles contained in one mole of a substance.
molar mass
the mass of one mole of a substance . Equal to the atomic mass ( or sum of atomic
masses)of the substance in grams.
Chemical reaction
The changing of substances into different substances by the breaking of old bonds and the formation of new bonds
Chemical equation
An expression representing a chemical reaction. (a recipe)
The formulas of the reactants(on the left) are connected by an arrow with the formulas of the products on the right.
Reactant
A starting substance in a chemical reaction
Product
A substance formed in a chemical reaction
Coefficient
A small whole number that
appears in front of a formula that indicated the number of molecules, atoms or formula units, of that substance
Subscript
a number that appears smaller than the normal type and slightly below to indicate the number
of that element in the compound
In a balanced chemical equation the mass is conserved.
Each side of the equation has the same number of atoms of each element.
November 12,2013
Blocks 1B,2B,5B
Chromatography
A method of separation of mixtures that relies on the difference in the attraction of
the components of the mixture to the chromatograph medium.
atom
single unit of an element (except for the diatomics)
molecule
single unit of a compound or diatomic element
formula unit
single unit of an ionic compound
mole
the amount of a substance that contains 6.02 x 10 exp23 representative particles of that substance. The mass is equal to its' atomic mass in grams of the substance.
Representative particle
the particle that a substance commonly exists in. Example: atoms, molecules, ions
Avogadro's number
6.02 x 10 exp 23
the number of representative particles contained in one mole of a substance.
molar mass
the mass of one mole of a substance . Equal to the atomic mass ( or sum of atomic masses)of the substance in grams.
November 4,2013
Blocks 1B,2B,5B
Chromatography
A method of
separation of mixtures that relies on the difference in the attraction of
the components of the mixture to the chromatograph medium.
November 30, 2012
*** Nuclear attraction increases left to right across a period and decrease top to bottom down a group due to the distance between the nucleus (+) and the outermost electrons(-)
Shielding effect
Inner (core) electrons shield the outermost electrons from the nuclear attraction.
Chemical bond
the force that holds two atoms together
cation
a positively charged ion
anion
a negatively charged ion
ionic bond
the electrostatic force that holds two oppositely charged ions together
ionic compound
compounds that contain ionic bonds.They are also known as salts
Electron dot to show the ionic bonding
The net charge of an ionic compound must equal zero.
Criss-Cross Method
November 28, 2012
Do now: Write the electron configuration, orbital notation, and electron dot structure for a magnesium atom and ion.
Periodic Trends
Atomic Radius is the term
used to describe the size of the atom.
The atomic radius of an
atom decreases as you move left to right across a period and increases as you
move from top to bottom down a
group.
Ion: an atom that aquires a charge by losing or gaining
electrons.
Octet rule: atoms tend to
gain,lose or share electrons in order to aquire a full set of 8 valence electrons (valence electron configuration of a nobel
gas).
Ionization energy:
The energy needed to remove
an electron from a gaseous atom.
The ionization energy of an
atom increases as you move left to right across a period and decreases as you
move top to bottom down a group.
Electronegativity:
an atoms ability to attract electrons while in a chemical bond. Electronegativity increases left to right across a period and decreases top to bottom down a group.
Click below to download the periodic trend worksheet students worked on in class
periodic_trends_worksheet.pdf | |
File Size: | 68 kb |
File Type: |
All three periodic trends can be explained with the same reasoning.
As you move across a period from left to right each atom has one proton and one electron more than the preceding atom. The protons are added to the nucleus increasing the nuclear charge. The electrons are added to the same energy level. All the electrons in the period have the same distance from the nucleus.
As you move down a group from top to bottom you are adding energy levels with each step down. The nuclear distance is increasing with each step down.
*** Nuclear attraction increases left to right across a period and decrease top to bottom down a group due to the distance between the nucleus (+) and the outermost electrons(-)
Shielding effect
Inner (core) electrons shield the outermost electrons from the nuclear attraction.
November 19 2012 Honors Chemistry
Electron Configuration
The arrangement of electrons in the atom
Rules for Electron Configuration
1) Aufbau Principle: electrons will always occupy the lowest energy orbitals available.
2) Pauli Exclusion Principle: a maximum of 2 electrons (with opposite spins) can occupy an orbital.
3) Hund's Rule: for equal energy orbitals, electrons will occupy each orbital before pairing up
November 21, 2012
Do Now:
Write the electron configuration for Helium
Click below to download the electron configuration worksheet from class
electron_configuration_worksheet.pdf | |
File Size: | 85 kb |
File Type: |