IS - 2 Fall Final

Kinetic Energy (KE)

Energy of movement, calculated as ½ mass x velocity (squared).

Potential Energy (PE)

Energy stored due to an object's position, calculated as mass x gravity x height.

Mechanical Energy (ME)

The sum of Kinetic Energy and Potential Energy, ME = KE + PE.

Conservation of Energy

Energy cannot be created or destroyed, only transferred or converted.

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 of an atom.

Mass Number

The total number of protons and neutrons in an atom.

Metals

Good conductors of heat and electricity, malleable, and ductile.

Nonmetals

Poor conductors, brittle (if solid), and many are gases at room temperature.

Ions

Atoms with a charge, formed by gaining or losing electrons.

Cations

Positive ions formed by losing electrons.

Anions

Negative ions formed by gaining electrons.

Isotopes

Atoms of the same element with different numbers of neutrons.

Fusion

The process of combining smaller atoms to form a larger one, releasing energy.

Fission

The process of splitting a large atom into smaller atoms, releasing energy.

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.

Energy of a photon (E)

Related to its frequency by the equation E = h⋅f.

Bohr Model

Describes electrons moving in discrete orbits around the nucleus, with quantized energy levels.

Atomic Radius

The distance from the nucleus to the outermost electron; it increases down a group and decreases across a period.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Affinity

The energy change when an atom gains an electron.

Electronegativity

Measures an atom's ability to attract electrons in a bond.

Covalent Bond

A bond where electrons are shared between atoms, typically between nonmetals.

Ionic Bond

A bond formed by the transfer of electrons from one atom to another, typically between a metal and a nonmetal.

Lewis Structures

Diagrams showing the arrangement of electrons in a molecule.

Octet Rule

Atoms tend to form bonds to achieve eight electrons in their valence shell.

Polarity

Bond polarity arises when two atoms with different electronegativities create partial charges.

Hydrogen Bonding (H-bond)

A strong dipole-dipole interaction between hydrogen and a highly electronegative atom.

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, while nonpolar solvents dissolve nonpolar solutes.

Molar Mass

The mass of one mole of a substance in g/mol.

Avogadro’s Number

6.022 x 10²³ particles per mole.

Molarity (M)

Concentration of a solution calculated as moles of solute divided by volume of solution in L.