IS - 2 Fall Final

Kinetic Energy (KE):
½ mass x velocity (squared)
Energy of movement
KE=Potential Energy (PE): Energy stored due to an object's position
Mass x gravity x height
Where mmm is mass, ggg is acceleration due to gravity (9.8 m/s²), and hhh is height.
Mechanical Energy (ME): The sum of KE and PE.
ME=KE+PE ME = KE + PE ME=KE+PE

Conservation of Energy: Energy cannot be created or destroyed, only transferred or converted.
In an isolated system:
Kinetic Energy Formula:
KE= ½ mass x velocity (squared)
Potential Energy Formula:
PE= Mass x gravity x heigh

Independent Variable: The variable that is changed or manipulated in an experiment.
Dependent Variable: The variable that is measured or affected by the independent variable.
Controlled Variables: Variables that are kept constant to ensure fair testing.
Control Group: A baseline group that is not exposed to the independent variable for comparison.

Atomic Number: The number of protons in the nucleus (top left corner of the element's symbol).
Symbol: The abbreviation for the element, typically one or two letters.
Mass Number: The total number of protons and neutrons in an atom (bottom number).

Metals, Nonmetals, and Metalloids:

Metals: Good conductors of heat and electricity, malleable, ductile.
Nonmetals: Poor conductors, brittle (if solid), and many are gases at room temperature.
Metalloids: Have properties of both metals and nonmetals, often semiconductors.

Ions: Atoms with a charge, formed by gaining or losing electrons.
- Cations: Positive ions (lost electrons).
- Anions: Negative ions (gained electrons).
Isotopes: Atoms of the same element with different numbers of neutrons, leading to different mass numbers.
- Same number of protons and electrons.
- Different number of neutrons, mass number, and possibly charge.

Fusion: The process of combining smaller atoms to form a larger one, releasing a large amount of energy. Occurs in stars like the Sun.
Fission: The process of splitting a large atom into smaller atoms, releasing energy. Used in nuclear reactors.
Half-Life: The time required for half of a sample of a radioactive substance to decay.

Wavelength : The distance between two successive crests or troughs of a wave.
Frequency : The number of waves that pass a point in one second.
c=λ⋅fc = \lambda \cdot fc=λ⋅f
Where ccc is the speed of light (3.00 × 10⁸ m/s).
Energy (E): The energy of a photon is related to its frequency.
E=h⋅fE = h \cdot fE=h⋅f
Where hhh is Planck's constant (6.626 × 10⁻³⁴ J·s).

Electrons move in discrete orbits around the nucleus.
Energy levels are quantized.
Absorption occurs when an electron jumps to a higher energy level; emission occurs when it falls to a lower energy level.

Atomic Radius: The distance from the nucleus to the outermost electron.
- Increases down a group, decreases across a period.
Ionization Energy: The energy required to remove an electron from an atom.
- Increases across a period, decreases down a group.
Electron Affinity: The energy changes when an atom gains an electron.
- Becomes more negative across a period, less negative down a group.
Electronegativity: A measure of an atom's ability to attract electrons in a bond.
- Increases across a period, decreases down a group.

Covalent Bond: Electrons are shared between atoms.
- Formed between nonmetals.
Ionic Bond: Electrons are transferred from one atom to another.
- Formed between a metal and a nonmetal.

Ionic Compounds:
- Metal + Nonmetal → Name metal, then nonmetal (with "-ide").
- Example: NaCl = Sodium Chloride.
Covalent Compounds:
- Nonmetal + Nonmetal → Use prefixes (mono-, di-, tri-, etc.).
- Example: CO₂ = Carbon Dioxide.
Lewis Structures: Diagrams showing how electrons are arranged in a molecule.
Octet Rule: Atoms tend to form bonds to achieve 8 electrons in their valence shell (except hydrogen, which follows the duet rule).
Formal Charge: A method of estimating the distribution of electrons in a molecule.
Polarity:
- Bond Polarity: A bond between two atoms with different electronegativities creates a dipole (partial positive and negative charges).
- Molecule Polarity: If the molecule has an asymmetric distribution of charge, it is polar.

Hydrogen Bonding (H-bond): A strong dipole-dipole interaction between hydrogen and a highly electronegative atom (N, O, F).
Dipole-Dipole: Attraction between polar molecules.
London Dispersion Forces: Weak attractions between nonpolar molecules due to temporary dipoles.

"Like dissolves like": Polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes.

Molar Mass: The mass of one mole of a substance (in g/mol).
Avogadro’s Number: 6.022 x 10 (23rd power) particles per mole.
Molarity (M): Concentration of a solution
M = moles of a solute / volume of solution in L

Dilution: When a solution is diluted, the moles of solute remain the same.