Regents High School Examination: Physical Setting/Chemistry

Vocabulary flashcards covering core concepts from the June 2025 Physical Setting/Chemistry Regents Examination, including atomic structure, bonding, kinetics, organic chemistry, and nuclear reactions.

Atomic History Sequence

The chronological development of the atomic model: hard sphere, followed by mostly empty space, and then electrons in shells outside a nucleus.

Atomic Mass of Chlorine

The weighted average of the atomic masses of the naturally occurring isotopes of chlorine.

Periodic Table Arrangement

The organization of elements in order of increasing atomic number.

Metalloid

A classification of elements represented by symbols such as $Te$ (tellurium).

Compound

A type of matter composed of two or more different elements chemically combined in a fixed ratio.

Mole Ratio

The relationship between substances in a reaction represented by the coefficients in a balanced equation.

Bond Formation Energy

During a reaction such as $Br + Br \rightarrow Br_2$, energy is released as bonds are formed.

Electronegativity

A term representing a property used to determine the degree of polarity in the bond between two atoms.

Kinetic Molecular Theory

A theory describing the particles of an ideal gas as being in random, constant, straight-line motion.

Effective Collision

A reaction occurrence when particles collide with both proper energy and proper orientation.

Heat of Reaction

The term representing the energy absorbed or released during a chemical change.

Entropy

A measure of disorder in a system; systems in nature tend to undergo changes toward lower energy and greater disorder.

Unsaturated Hydrocarbon

A hydrocarbon molecule containing multiple bonds, such as $2\text{-butyne}$.

Arrhenius Base

A substance that yields hydroxide ions ($OH^-$) as the only negative ions in an aqueous solution.

Nuclear Fission

A nuclear reaction that results in the net conversion of mass to energy.

Excited State

An electron configuration where electrons have absorbed energy and moved to higher shells, such as $2\text{--}7\text{--}1$ for a neon atom.

Catalyst

A substance that increases the reaction rate by providing a different reaction pathway with a lower activation energy.

Distillation

A laboratory process used to separate a mixture of two different liquids based on their different boiling points.

Isotopes

Atoms of the same element that have the same number of protons but a different number of neutrons.

Chemical Equilibrium

A state in a sealed system where the rate of the forward reaction is equal to the rate of the reverse reaction.

Transmutation

A type of reaction, such as $^{15}_{8}\text{O} \rightarrow ^{0}_{+1}\text{e} + ^{15}_{7}\text{N}$, where one element changes into another.

Voltaic Cell

An electrochemical cell that converts chemical energy to electrical energy.

Electrolytic Cell Oxidation

The process of losing electrons which occurs at the anode in an operating electrolytic cell.