Chemistry Regents Comprehensive Review Flashcards

This set of flashcards covers critical concepts required for the Chemistry Regents exam, including atomic structure, nuclear chemistry, matter, energy, gas laws, periodic table trends, bonding, stoichiometry, solutions, kinetics, equilibrium, acids/bases, redox, and organic chemistry.

Scientific Method: Variables

When doing an experiment, all variables must remain the same except the variable you are testing.

Subatomic Particles: Protons

Particles located in the nucleus with a $+1$ charge and a mass of $1\,amu$; the number of these defines the atomic number.

Subatomic Particles: Neutrons

Particles located in the nucleus with a $0$ charge and a mass of $1\,amu$ (atomic mass unit).

Subatomic Particles: Electrons

Negatively charged particles ($-1$ charge) with a mass of $0\,amu$, located in orbitals (clouds) around the nucleus.

Mass Number

The total sum of the \text{#protons} + \text{#neutrons} in an atom.

Isotopes

Atoms of the same element with the same number of protons but a different number of neutrons, resulting in a different mass number.

Average Atomic Mass

The weighted average of all naturally occurring isotopes for a specific element.

Rutherford Gold Foil Experiment

An experiment showing that an atom is mostly empty space with a small, dense, positively charged nucleus.

Wave-mechanical Model

The electron cloud model showing that an orbital is the most probable location of electrons.

Ion

A charged element produced by the loss or gain of electrons.

Valence Electrons

Electrons found in the outermost shell, representing the last number in an electron configuration.

Excited State to Ground State

A transition where an electron moves to a lower energy level, emitting a specific amount of energy, sometimes as a bright line spectrum.

Beta Particle

A particle with a $-1$ charge and mass of $0$, having less mass and greater penetrating power than an alpha particle.

Gamma Radiation

The form of nuclear radiation with the greatest penetrating power.

Natural Transmutation

Spontaneous radioactive decay involving one reactant forming two products as elements change.

Fusion

A nuclear reaction where light nuclei combine to form a heavy nucleus, releasing more energy than fission.

Fission

A nuclear reaction involving the splitting of a heavy nucleus into smaller pieces.

Radioisotopes: Dating

The use of $C-14$ (Carbon-14) to determine the age of geological formations and organic matter.

Radioisotopes: Medical

$I-131$ is used to diagnose thyroid disorders, while $Co-60$ is used to treat cancer.

Element

A substance that cannot be broken down by chemical means.

Compound

A substance composed of two or more elements that can be broken down by chemical means.

Diatomic Molecules (BrINClHOF)

Molecules containing two of the same atom bonded together: $Br_2$, $I_2$, $N_2$, $Cl_2$, $H_2$, $O_2$, and $F_2$.

Homogeneous Mixture (Solution)

A mixture featuring an even distribution of particles, often denoted by the symbol $(aq)$, meaning dissolved in water.

Distillation

A physical separation method that separates liquids based on their different boiling points.

Chromatography

A method of separating particles in a mixture based on their solubility and polarity.

Sublimation

A phase change where a substance goes directly from a solid to a gas, such as with $CO_2$.

Phase Change Diagram: Flat Parts

Sections of the graph representing phase changes where Potential Energy ($PE$) changes and Kinetic Energy ($KE$) remains constant.

Density Formula

$\text{Density} = \frac{\text{mass}}{\text{volume}}$ ($g/L$ or $g/cm^3$).

Average Kinetic Energy

The scientific definition of temperature.

Heat of Vaporization

The amount of heat required to vaporize a substance, which for water is $2260\,J$ or $2.26 \times 10^3\,J$.

$$Q=mC\Delta T$$

The formula for heat where $q$ is heat, $m$ is mass, $C$ is specific heat capacity, and $\Delta T$ is the change in temperature.

Endothermic

A process where energy is absorbed, often shown on the left side of a chemical equation.

PLIGHT

A mnemonic for Ideal Gas conditions: Pressure Low, Ideal Gas, High Temperature.

Metals

Elements located to the left of the staircase that are malleable and good conductors of heat and electricity.

Noble Gases (Group 18)

Relatively non-reactive elements that are stable due to having a full outer shell of 8 valence electrons.

MELPS

A mnemonic for metals: Metals Electrons Lost form Positive Smaller ions.

Electronegativity

A measure of an atom's attraction for electrons within a chemical bond.

Periodic Table Trends: Ionization Energy

Increases from left to right across a period and decreases from top to bottom down a group.

BARF

A mnemonic for bonding: Bond Broken energy Absorbed (endothermic), energy Released bond Formed (exothermic).

Ionic Bond

A bond formed between a metal and a nonmetal (or involving Table E ions) via the transfer of electrons.

Covalent Bond

A bond formed between nonmetals, involving the sharing of electrons.

SNAP

A mnemonic for molecule polarity: Symmetrical Nonpolar, Asymmetrical Polar.

Hydrogen Bonding

A strong intermolecular force occurring between Hydrogen ($H$) and Fluorine ($F$), Oxygen ($O$), or Nitrogen ($N$).

GFM (Gram Formula Mass)

Also known as molar mass; the sum of the masses of each element in a formula multiplied by their subscripts.

Empirical Formula

The most simplified integer ratio formula of a compound.

Table G: Solubility

Reference used to determine if a salt solution is saturated (on the line), unsaturated (below the line), or supersaturated (above the line).

Colligative Properties: Salt Addition

Adding a salt to water causes the freezing point to decrease and the boiling point to increase.

Molarity ($M$)

The concentration of a solution measured as $\frac{\text{moles}}{\text{L}}$.

Effective Collisions

Chemical reactions occur when particles collide with sufficient energy and proper orientation.

Catalyst

A substance that speeds up a reaction by providing a different reaction pathway that lowers the activation energy.

Entropy

A measure of disorder; gases have the highest entropy, while solids have the lowest.

Equilibrium

A state in a closed system where the rate of the forward reaction equals the rate of the reverse reaction and concentrations remain constant.

Le Chatelier's Principle: Mnemonic

UP and AWAY, DOWN and TOWARDS (referring to concentration shifts).

Arrhenius Theory

Acids yield $H^+$ (hydronium) ions in solution, while bases yield $OH^-$ (hydroxide) ions.

Alternate Acid-Base Theory (BAAD)

Bases Accept $H^+$; Acids Donate $H^+$.

Neutralization

A reaction where an $\text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water}$.

Titration

A laboratory technique used to determine the concentration of an unknown acid or base ($MaVa = MbVb$).

Oxidation

The loss of electrons, resulting in an increase in oxidation number (LEO).

Reduction

The gain of electrons, resulting in a decrease in oxidation number (GER).

AN OX RED CAT

A mnemonic for redox cells: Anode = Oxidation; Reduction = Cathode.

Voltaic Cell

A device where chemical energy is converted to electrical energy spontaneously; ions move through a salt bridge.

Electrolytic Cell

A device that uses electrical energy (from a battery) to drive a non-spontaneous chemical reaction (electrolysis).

Saturated Hydrocarbons

Compounds containing only carbon and hydrogen with all single bonds between carbon atoms (alkanes).

Unsaturated Hydrocarbons

Organic compounds that contain double or triple bonds between carbon atoms (alkenes or alkynes).

Isomers

Compounds that have the same molecular formula but different structural arrangements, resulting in different properties.

Saponification

An organic reaction used for the production of soap.

Fermentation

An organic reaction where $\text{sugar} + \text{enzyme} \rightarrow \text{ethanol (alcohol)} + \text{carbon dioxide}$.