Chemistry and General Science Flashcards

Vocabulary flashcards for quick review of key concepts in Chemistry and General Science based on the provided lecture notes.

Chemistry

The study of matter and its properties.

Matter

Anything that takes up space and has mass.

Mass

A measure of the number of particles in an object.

Weight

The influence of gravity on mass.

Density

Mass per unit volume. D=m/v

Substance

Any variety of matter with identical properties and composition; classified as elements or compounds.

Elements

Cannot be broken down chemically;Basic building block of matter.

Compounds

Can be broken down chemically; formed from the bonding of two or more elements.

Mixtures

The results of the combination of elements and/or compounds where the substances are not chemically combined.

Homogeneous Mixture

Have only one phase, or have a uniform appearance throughout.

Heterogeneous Mixture

Mixtures that are made up of more than one phase or of different parts and can be separated physically.

Physical Properties

Observable and measurable properties of substances, such as phase, color, odor, density, boiling or melting point.

Chemical Properties

Properties observed when a substance reacts with other substances, resulting in substances with different physical properties.

Energy

The ability to do work; conserved, meaning it is not created or destroyed.

Potential Energy

Stored energy.

Kinetic Energy

Moving energy.

Exothermic Reaction

A reaction where more energy is released than absorbed.

Endothermic Reaction

A reaction where more energy is absorbed than released.

Activation Energy (Ea)

The energy required to start a reaction.

Heat of Reaction (ΔH)

The change in the energy of the reactants or products; also known as enthalpy.

Solid

Definite shape and volume. Atoms in a fixed, regular geometric pattern.

Liquid

Definite volume, but no definite shape. Molecules are constantly touching, but not in a fixed position.

Gas

No definite volume or shape. Molecules are spread far apart.

Plasma

An ionized gas where the particles are electrically charged.

Kinetic Molecular Theory (KMT)

Explains the behavior of gases: gas molecules are individual particles in straight-line random motion, continuously collide and transfer energy, negligible volume, and no attraction between molecules.

Pressure

Amount of force exerted on an area by a gas as molecules collide.

Boyle's Law

At constant temperature, there is an inverse relationship between pressure and volume (P₁V₁ = P₂V₂).

Charles' Law

At constant pressure, there is a direct relationship between temperature and volume (V1/T1 = V2/T2).

Temperature

Average kinetic energy of a sample.

Standard Temperature and Pressure (STP)

Defined as 0°C and 1 atm (273 K and 760 torr).

Combined Gas Law

Combines Charles' and Boyle's Laws (P₁V₁/T₁ = P₂V₂/T₂).

Dalton's Law of Partial Pressures

The total pressure exerted by a mixture of gases is equal to the sum of the pressures exerted by the individual gases (Ptotal = Pgas1 + Pgas2 + Pgas3…).

Avogadro's Law

Equal volumes of gases will contribute to the total pressure equally.

Ideal Gas Law

Relates pressure, volume, temperature, and moles of a gas (PV = nRT).

Mole

A unit of measurement equal to 6.02 x 10^23 of something (Avogadro's Number).

Vaporization/Evaporation

The process where molecules at the surface of a liquid can achieve enough kinetic energy to overcome the forces between them and they can move into the gas phase.

Vapor Pressure

The amount of force as the molecules of the liquid enter the gas phase.Vapor pressure depends upon the temperature of the liquid.

Normal Boiling Point

Temperature at which liquid will boil when the atmospheric pressure is 760 torr.

Sublimation

The process where a solid changes directly into a gas phase, without any apparent liquid phase in between.

Deposition

The process where a gas will form a solid, again without any apparent liquid phase in between.

Mass Number

The sum of the protons and neutrons in the nucleus of the atom.

Atomic Number

The number of protons in the nucleus, the nuclear charge, or the number of electrons in a neutral atom.

Isotopes

Atoms with the same atomic number but different mass numbers (different number of neutrons).

Atomic Mass

Takes into account all of the masses of the isotopes of an atom and their relative abundance.

Valence Electrons

Electrons in the outermost principal energy level; important in forming chemical bonds.

Principal Quantum Number (n)

Represents the principal energy level that the electron is in.

Ion

An atom that has gained or lost electrons, resulting in a net electrical charge.

Cation

An ion with a positive charge (atom loses electrons).

Anion

An ion with a negative charge (atom gains electrons).

Octet Rule

Atoms gain or lose electrons to achieve eight valence electrons in the outermost principal energy level, resulting in a stable electron configuration.

Metals

Ductile, malleable, conduct heat and electricity, have a shiny luster, and tend to lose electrons.

Nonmetals

Brittle, lack luster, and are poor conductors of heat and electricity; tend to gain electrons and form anions.

Semimetals (Metalloids)

Exhibit some properties of metals and some of nonmetals.

Electronegativity

A measure of an atom's ability to attract electrons.

Ionization Energy

The energy needed to remove an electron from an atom and form an ion.

Atomic Radius

The distance from its nucleus to the outermost electron of that atom.

Intramolecular Bonds

Bonds that are found within molecules; hold atoms to other atoms.

Intermolecular Bonds

Bonds between molecules; give substances their varying melting points, boiling points, and vapor pressures.

Ionic Bond

Very strong bonds that are formed between a cation and an anion.

Covalent Bond

Bonds formed when two nonmetal atoms share electrons.

Nonpolar Covalent Bond

Equal sharing of electrons between atoms due to similar electronegativities.

Polar Covalent Bond

Unequal sharing of electrons between atoms due to differing electronegativities.

Coordinate Covalent Bond

A covalent bond in which one atom donates both electrons.

Network Solids

Substances where atoms bond to each other in a continuous network, not forming molecules.

Metallic Bond

Bond that occurs between metals where electrons are loosely bound.

Dipole

A molecule that has a “buildup” of negative charge on one side and a positive charge on another side.

Hydrogen Bonding

A weak force that comes about when hydrogen is bonded to fluorine, oxygen, or nitrogen.

Van der Waals (London Dispersion) Forces

A very weak, temporary attraction between nonpolar molecules caused by temporary uneven charge distribution.

Stoichiometry

The branch of chemistry that deals with the amounts of products produced from certain amounts of reactants.

Molecular Formulas

Indicate the total number of atoms of each element that are present in a covalently bonded molecule.

Empirical Formulas

The lowest ratio of the elements present in the compound is used.

Synthesis Reaction

Many substances come together to form one compound: A + B → AB.

Decomposition Reaction

One compound breaks down into many substances: YZ → Y + Z.

Single Replacement Reaction

One element replaces one other element: A + BC → B + AC.

Double Replacement Reaction

Two elements switch partners: AB + XY → AY + XB.

Mole Ratio

The ratio of the number of moles of one substance to the number of moles of another substance in a balanced chemical equation.

Science

A systematic study that is concerned with facts, principles, and methods that could be observed in our natural or physical environment.

Technology

The application of scientific knowledge to improve life or satisfy needs.

Force

Anything that changes speed and direction of moving objects or that which causes a stationary object to start moving in a straight line.

Friction

The force which acts between surfaces of objects in contact where one or both objects move or are about to move relative to each other.

Work

An object is equal to the product of the magnitude of the force exerted on the object and the distance that the object moves while the force is being exerted.

Inclined Plane

A flat surface or ramp used to move objects across distances.

Wedge

A kind of inclined plane used to push things apart.

Screw

An inclined plane wrapped around a cylinder.

Lever

An arm that pivots against a fulcrum used to pry something loose.

Wheel and Axle

A wheel that turns the axle causing movement of objects across distances.

Pulley

A cord wraps around a wheel that's used to raise and lower object.

Cohesion

The attraction between molecules of the same kind.

Adhesion

Attraction between molecules of different kinds.

Plasma

An ionized gas where the particles are electrically charged.

Thermoplastics

Softens when heated and can be formed again and again

Thermosetting plastic

when heated and then cooled becomes permanently set in shape at which it is cooled.

Metal Alloy

is composed of a metal element to which small amounts of other metals or nonmetals are mixed to improve its properties.

Biomass

is a clean renewable energy resource that can be burned directly as fuel or converted to a more convenient form and then burned. Its primary sources are forest products and agricultural wastes.

Fossil fuels

such as coal, oil and gas are also derived from biological material; however, these materials were formed from organic remains from prehistoric time! Simply put, fossil fuels are just ancient biomass.

Atmospheric Pressure

is the weight of a column of air on a unit horizontal area.

Air Pollutant

is any substance that both physically and chemically changes the properties of air thus making it harmful.

Materials' Properties

Elasticity, Ductility, Malleability, Toughness and Brittleness

Melting Point

defined as the temperature at which a solid begins to melt.

Boiling Point

is defined as the temperature at which a liquid starts changing into the gaseous phase.