Grade 11 Chemistry practicing flashcards

Comprehensive vocabulary flashcards covering the major topics of the Grade 11 Chemistry textbook, including atomic theory, chemical bonding, states of matter, kinetics, equilibrium, and organic oxygen-containing compounds.

Atomos

A term used by the Greek philosopher Democritus (460–370 BC) to describe tiny, indestructible particles meaning "indivisible".

Law of Conservation of Mass

One of the fundamental laws based on the finding that mass is neither created nor destroyed during a chemical reaction.

Law of Definite Proportions

A law stating that a given chemical compound always contains its component elements in fixed ratio by mass, regardless of the source.

Cathode Rays

Rays that originate from the negative electrode (cathode) in an evacuated glass tube and consist of a beam of negatively charged particles called electrons.

Charge of an Electron

Determined by Robert A. Millikan in 1909 as $e = -1.602 \times 10^{-19} \text{\,C}$.

Radioactivity

The spontaneous emission of particles and/or radiation from the unstable nuclei of certain atoms such as uranium or radium.

Alpha ($\alpha$) Rays

Positively charged particles identical to helium nuclei, possessing a mass about four times that of a hydrogen atom.

Gamma ($\gamma$) Rays

High-energy radioactive radiation that carries no charge and is not affected by external electric or magnetic fields.

Plum-pudding Model

An atomic model proposed by J.J. Thomson where electrons and protons are randomly distributed in a positively charged cloud.

Neutron

A neutral nuclear particle with a mass of $m_n = 1.67493 \times 10^{-27} \text{\,kg}$, discovered by James Chadwick in 1932.

Atomic Number ($Z$)

The number of protons in the nucleus of each atom of an element.

Mass Number ($A$)

The total number of protons and neutrons in the nucleus of an atom.

Isotopes

Atoms of an element that have the same atomic number ($Z$) but different numbers of neutrons and therefore different mass numbers ($A$).

Wavelength ($\lambda$)

The distance a wave travels during one cycle, expressed in meters ($m$), nanometers ($nm$), or angstrom ($\text{\AA}$).

Quantum

A small "packet" or bundle of energy; according to Max Planck, energy is emitted or absorbed only in these discrete quantities.

Photon

A particle of light or energy packet used by Albert Einstein to explain the photoelectric effect.

Threshold Frequency ($\nu_o$)

The minimum frequency of light required to eject electrons from the surface of a metal in the photoelectric effect.

Ground State

The lowest energy state of an atom, corresponding to $n = 1$ in the Bohr model of the hydrogen atom.

Heisenberg Uncertainty Principle

The principle stating it is impossible to know with great certainty both an electron’s position ($\Delta x$) and its momentum ($\Delta p$) at the same time.

Orbital

A mathematical solution ($\psi^2$) indicating the region in space where an electron is most likely to be found.

Principal Quantum Number ($n$)

An integer ($n = 1, 2, 3, \dots$) that describes the main energy level or shell an electron occupies.

Hund’s Rule

Principle stating that equal energy (degenerate) orbitals are each occupied by a single electron before any orbital receives a second electron.

Valence Electrons

The electrons in the outermost principal quantum level of an atom, which are involved in chemical bonding.

Octet Rule

The observation that atoms tend to gain, lose, or share electrons until they achieve an outer shell containing eight electrons ($ns^2np^6$).

Ionic Bond

A bond formed by the electrostatic attraction between positive cations and negative anions following the transfer of electrons.

Lattice Energy ($U$)

The enthalpy change that occurs when $1 \text{\,mol}$ of ionic solid separates into gaseous ions.

Coordinate Covalent Bond

A covalent bond formed when one atom donates both electrons in the shared pair; also known as a dative bond.

Resonance

A condition where two or more valid Lewis structures (resonance forms) can be written for a single molecule, resulting in a resonance hybrid.

VSEPR Theory

Valence Shell Electron Pair Repulsion theory; used to predict molecular geometry based on the idea that electron pairs repel each other.

Sigma ($\sigma$) Bond

A covalent bond formed by the head-to-head overlap of atomic orbitals, with electron density concentrated along the internuclear axis.

Pi ($\pi$) Bond

A covalent bond formed by the sideways or lateral overlap of parallel p-orbitals, with electron density lobes above and below the sigma bond axis.

Hybridization

The mixing of atomic orbitals in an atom to produce new set of equivalent hybrid orbitals ($sp$, $sp^2$, $sp^3$, etc.).

Plasma

The fourth physical state of matter consisting of a gaseous mixture of positive ions and electrons, existing at extremely high temperatures.

Boyle’s Law

States that at constant temperature, the volume of a fixed mass of gas is inversely proportional to the pressure ($P_1V_1 = P_2V_2$).

Charles’ Law

States that at constant pressure, the volume of a fixed mass of gas varies directly with its Kelvin temperature ($\frac{V_1}{T_1} = \frac{V_2}{T_2}$).

Ideal Gas Equation

The formula $PV = nRT$, relating pressure, volume, temperature, and quantity of an ideal gas.

Graham’s Law of Diffusion

States that the rate of diffusion ($r$) of a gas is inversely proportional to the square root of its density ($d$) or molar mass ($M$).

Sublimation

The physical process in which a substance changes directly from the solid state to the vapor state without passing through the liquid state.

Chemical Kinetics

The study of the rates of chemical reactions and the mechanisms by which they occur.

Activation Energy ($E_a$)

The minimum amount of energy required for a chemical reaction to occur upon collision of reactants.

Catalyst

A substance that increases the rate of reaction by providing a different mechanism with a lower activation energy ($E_a$).

Dynamic Equilibrium

A state in which the rate of the forward reaction equals the rate of the reverse reaction, resulting in constant concentrations.

Le Chatelier’s Principle

The principle stating that if a stress is applied to a system at equilibrium, the system will shift to relieve that stress.

Haber Process

Industrial synthesis of ammonia from nitrogen and hydrogen gases using an iron catalyst and compromising conditions ($500 \text{\,\textdegree C}$, $200-400 \text{\,atm}$).

Esterification

A condensation reaction in which a carboxylic acid and an alcohol react in the presence of an acid catalyst to form an ester and water.

Saponification

The base-catalyzed hydrolysis of an ester (typically a triglyceride) to form a carboxylate salt and an alcohol.

Rancidity

The deterioration of fats and oils resulting in unpleasant odors, caused by hydrolysis or oxidation.