11th Grade Chemistry - Vocabulary Flashcards

Flashcards for reviewing key chemistry vocabulary and concepts from Higher Secondary First Year Chemistry Volume - I, Government of Tamil Nadu.

Element

A substance that consists of only one type of atom.

Compound

A substance made up of molecules containing two or more atoms of different elements.

Relative Atomic Mass (Ar)

The ratio of the average mass of the atom to the unified atomic mass unit.

Average Atomic Mass

The average of the atomic masses of all atoms in their naturally occurring isotopes.

Relative Molecular Mass

The ratio of the mass of a molecule to the unified atomic mass unit; calculated by adding the relative atomic masses of its constituent atoms.

Mole

The SI unit representing a specific amount of a substance, containing as many elementary particles as there are atoms in 12 g of carbon-12 isotope.

Avogadro Number

The total number of entities present in one mole of any substance, equal to 6.022 x 10^23.

Molar Mass

The mass of one mole of a substance, typically expressed in g mol-1.

Molar Volume

The volume occupied by one mole of a substance in the gaseous state at a given temperature and pressure.

Gram Equivalent Mass

The mass of an element, compound, or ion that combines with or displaces 1.008 g of hydrogen, 8 g of oxygen, or 35.5 g of chlorine.

Empirical Formula

A chemical formula showing the simplest ratio of elements in a compound.

Molecular Formula

A chemical formula showing the actual number of atoms of each element in a molecule of the compound.

Stoichiometry

The numerical relationship between chemical quantities in a balanced chemical equation.

Limiting Reagent

The reactant that is completely consumed in a chemical reaction, determining the amount of product formed.

Oxidation

The loss of electrons by a molecule, atom, or ion.

Reduction

The gain of electrons by a molecule, atom, or ion.

Oxidizing agent

A substance that causes oxidation by accepting electrons in a redox reaction, and is itself reduced.

Reducing agent

A substance that causes reduction by donating electrons in a redox reaction, and is itself oxidized.

Oxidation Number

The imaginary charge left on the atom when all other atoms of the compound have been removed in their usual oxidation states.

Combination Reaction

A reaction in which two or more substances combine to form a single compound.

Decomposition Reaction

A reaction in which a compound breaks down into two or more components.

Displacement Reaction

A reaction in which an ion or atom in a compound is replaced by an ion or atom of another element.

Disproportionation Reaction

A redox reaction where the same compound undergoes both oxidation and reduction.

Monatomic Unit

An element existing as single atoms (e.g., Gold - Au, Copper - Cu).

Polyatomic Unit

An element existing as multiple atoms bonded together (e.g., Hydrogen - H2, Phosphorus - P4).

Quantum Numbers

A set of numbers that describe the properties of an electron in an atom, including energy level, shape, spatial orientation, and spin.

Aufbau Principle

The principle stating that electrons fill atomic orbitals in order of increasing energy levels.

Hund's Rule

The rule stating that electron pairing in degenerate orbitals does not occur until each orbital contains one electron.

Pauli Exclusion Principle

The principle that no two electrons in an atom can have the same set of four quantum numbers.

Node

A region in an atom where the probability of finding an electron is zero.

Degenerate Orbitals

Orbitals having the same energy level.

Effective Nuclear Charge

The net positive charge experienced by an electron in a multi-electron atom.

Shielding Effect

The reduction in the effective nuclear charge on an electron cloud due to the presence of other electron shells.

Valence electrons

Electrons in the outermost shell of an atom that determine its chemical properties.

Amphoteric

A substance that can act as both an acid and a base.

Hydrolysis

A chemical reaction in which water is used to break down a compound.

Hydration

The process of surrounding ions or molecules with water molecules.

Alkali Metals

Group 1 elements of the periodic table, known for being reactive metals that form alkaline solutions when reacted with water.

Alkaline Earth Metals

Group 2 elements of the periodic table, known for forming alkaline solutions when reacted in water, though less soluble compared to alkali metals.

Lanthanides

The 14 elements following lanthanum in the periodic table, atomic numbers 58-71.

Actinides

The 14 elements following actinium in the periodic table, atomic numbers 90-103.

Enthalpy

The sum of the internal energy of a system and the product of its pressure and volume reflecting the capacity to release heat or do mechanical work.

Spontaneous Process

A process that occurs under a given set of conditions without the need for any external driving force.

Non-Spontaneous Process

A process that will not occur unless driven by a continuous external force.

Gibbs Free Energy

A thermodynamic potential that measures the amount of energy available in a chemical or physical system to do useful work at a constant temperature and pressure.

Adiabatic Process

A process that occurs without the transfer of heat or matter between a system and its surroundings.

Isothermal Process

A process that occurs at a constant temperature.

Isobaric Process

A process that occurs at a constant pressure.

Isochoric Process

A process that occurs at constant volume

Cyclic Process

A series of thermodynamic processes that returns a system to its initial state.

Third Law of Thermodynamics

States that the entropy of a perfect crystalline substance at absolute zero is zero.

Second Law of Thermodynamics

The entropy of an isolated system increases during a spontaneous process.