Chemistry
Scientific Measurement
Atoms (Atomic Theory)
Arrangement of Electrons
Atomic Structure
History
Thompson
Dalton
Rutherford
Bohr
Significant Figures
Zeros appearing in front of all nonzero digits are not significant
Acid- Base Reactions
Periodic Law
Chemical bonding
Chemical Formulas and Chemical Compounds
Chemical Equations and Reactions
Gases
Stoichiometry
Molarity
Gold Foil Experiment
The Gold Foil Experiment is when scientist discovered that every atom contains a nucleus where all of the atom's protons and most of its mass is located.
Zeros at the end of a number and to the right of a decimal point are significant
Zeros appearing between nonzero digits are significant
John Dalton proposed an explanation for the law of multiple proportions, law of conservation of mass, and the law of definite proportions.
5 postulates of Dalton's theory:
- All matter is composed of extremely small particles.
- Atoms of a given element are identical in size, mass, and other properties; atoms of different elements differ in size, mass, and other properties.
Today we know that atoms are divisible into even smaller particles and a given element can have atoms with different masses.
Cathode Rays and Electrons
- Atoms cannot be subdivided, created, or destroyed.
- Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
In chemical reactions, atoms are combined, separated, rearranged.
Cathode rays were deflected by a magnetic field in the same manner as a wire carrying electric current, which was known to have a negative charge.
The rays were deflected away from a negatively charged object
A paddle wheel placed on rails between the electrodes rolled along the rails from the cathode toward the anode
An object placed between the cathode and the opposite end of the tube cast a shadow on the glass
Rutherford concluded that rebounded alpha particles experienced some powerful force within the atom, and that the source of the force must occupy a very small amount of space.
Rutherford's student
Ionization Energy
Alkali Metals
Alkaline Earth Metals
Noble Gases
Atomic Radius
Electronegativity
Electron Configuration of Ions
Halogens
Transition Metals
Lanthanides/Actinides
SI Base Units
Examples:
Bohr explained what happens inside of an atom and developed a picture of atomic structure.
measure of the ability of an atom to attract electrons from another atom.
Period Trends
Group Trends
Tends to increase across a period because valence shells are closer to being filled.
Alkaline Earth Metals are group two on the periodic table, second most reactive family of elements, and they all have two valence electrons.
Tends to decrease down a group or stay the same.
Fluorine has the highest electronegativity.
Group one on the periodic table.
Group 18 on the periodic table
Group 17 on the periodic table
Types of bonds
Molecular Geometry
Lewis Structures
Ionic Bond
Covalent Bond
Nonpolar Covalent Bond
Polar Covalent Bond
forms when valence electrons are transferred from one atom to another. In ionic compounds the ions are arranged in a crystal lattice. Strong forces hold the ions together. Electronegativity difference greater than or equal to 1.7.
A unit of length would be measured using the SI unit "meter."
A unit of time would be measured using the SI unit "seconds."
electrons are shared equally because atoms have the same electronegativities . Electronegativity difference less than or equal to 0.3
A unit of mass would be measured using the SI unit "kilogram."
electrons are shared unequally, creating partially charged ends or poles. Electronegativity difference between 1.7 and 0.3.
Zeros at the end of a number but to the left of a decimal point may or may not be significant. If a zero has not been measured or estimated but is just a placeholder, it is not significant. A decimal point placed after zeros indicates that they are significant.
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Metallic Bond
electrons are delocalized( creates sea of electrons)
linear
diagram representing the arrangement of valence electrons in a molecule. Most atoms need 8 valence electrons to become stable. The exceptions are H and He which need only 2 valence electrons to be stable. The central atom is frequently Carbon or the atom with the smallest electronegativity. Double or triple bond: SiCONS. Diatomic Elements: HOFBrINCl.
The number of protons in an atom is equal to the number of electrons
Electrons are arranged in "energy levels" around the nucleus.
Quantum Numbers
Principal Quantum Number(n): represents the main energy level of electrons
Angular Momentum Quantum Number(l): describes the orbital shape within an energy level.
Polyatomic Ion covalently bonded group of ions with a charge.
Magnetic Quantum Number(m): describes orientation of orbital in space.
Spin Quantum Number(s): describes spin of electron in orbital.
Orbital shapes
S(level 1)= 1 orbital x 2 electrons/ orbital= 2 electrons
P(level 2= 3 orbitals x 2 electrons/ orbital= 6 electrons
D(level 3)= 5 orbitals x 2 electrons/ orbitals= 10 electrons
F(level 4)= 7 orbitals x 2 electrons/ orbital= 14 electrons
The theory that all matter is made up of tiny indivisible particles(atoms)
a short hand way of reporting the details of a chemical reaction
Reactants
Products
Coefficients
used to balance equations. represents the number of molecules, formula units, or atoms of the substance.
the starting substances in a reaction and are placed on the left side of the equation
the substances produced during a chemical reaction and are placed on the right side of the equation
arrow is read as yields
Balancing Equations
Rules: Making element inventory
Begin with large molecules or formula unit of the substance containing the most atoms
Balance polyatomici ions that appear on both sides of the equation as a single unit
Balance Hydrogen and Oxygen atoms last
Formula;
mass A to mole A use the molar mass
mole A to mole B use the molar ratio(coefficients in the balanced equation)
mole B to mass B use the molar mass