Chem. Vocab

Mass

(m) Compare with weight .Mass is a measure of the tendency of an object to resist acceleration. It's harder to roll a tractor trailer than a roller skate; the tractor trailer has a far greater mass.

Nonmetal

(metal,metalloid) A nonmetal is a substance that conducts heat and electricity poorly, is brittle or waxy or gaseous, and cannot be hammered into sheets or drawn into wire. Nonmetals gain electrons easily to form anions . About 20% of the known chemical elements are nonmetals.

Group

1. A substructure that imparts characteristic chemical behaviors to a molecule, for example, a carboxylic acid group. 2. A vertical column on the periodic table, for example, the halogens . Elements that belong to the same group usually show chemical similarities, although the element at the top of the group is usually atypical.

Chemical Property

A chemical property is any of a material's properties that becomes evident during a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity. Simply speaking, chemical properties cannot be determined just by viewing or touching the substance; the substance's internal structure must be affected for its chemical properties to be investigated. However a catalytic property would also be a chemical property.

Chemical Reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes may both occur.

Pure Substance

A sample of matter that cannot be separated into simpler components without chemical change . Physical changes can alter the state of matter but not the chemical identity of a pure substance. Pure substances have fixed, characteristic elemental compositions and properties.

Solid

A solid is a relatively dense, rigid state of matter, with a definite volume and shape. Molecules in solids are often packed close together in regularly repeating patterns, and vibrate around fixed positions.

Liquid

A state of matter that has a high density and is incompressible compared to a gas. Liquids take the shape of their container but do not expand to fill the container as gases do. Liquids diffuse much more slowly than gases

Chemical Change

Chemical changes occur when a substance combines with another to form a new substance, called synthesis or, alternatively, decomposes into two or more different substances. These processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. Some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. Understanding chemical changes is a major part of the science of chemistry. A chemical change is a dissociation, recombination, or rearrangement of atoms.

Physical Property

Compare with chemical property .Measurement of a physical property may change the arrangement but not the structure of the molecules of a material. Examples of physical properties are density, color, boiling point, volume, temperature, and mass.

Compound

Compare with element and mixture .A compound is a material formed from elements chemically combined in definite proportions by mass. For example, water is formed from chemically bound hydrogen and oxygen. Any pure water sample contains 2 g of hydrogen for every 16 g of oxygen.

Intensive Property

Compare with extensive property .A property that does not change when the amount of sample changes. Examples are density, pressure, temperature, color.

Solution

Compare with heterogeneous mixture , element and compound .A sample of matter consisting of more than one pure substance with properties that do not vary within the sample.

Extensive Property

Compare with intensive property .A property that changes when the amount of matter in a sample changes. Examples are mass, volume, length, and charge.

Metalloid

Compare with metal and nonmetal .An element with both metallic and nonmetallic properties

Atom

Compare with molecule and ion .An atom is the smallest particle of an element that retains the chemical properties of the element. Atoms are electrically neutral, with a positively charged nucleus that binds one or more electrons in motion around it.

Metal

Compare with nonmetal and metalloid .A metal is a substance that conducts heat and electricity, is shiny and reflects many colors of light, and can be hammered into sheets or drawn into wire. Metals lose electrons easily to form cations . About 80% of the known chemical elements are metals.

Reactant

Compare with product .A substance that is consumed during a chemical change .

Product

Compare with reactant .A substance that is produced during a chemical change .

Heterogeneous (Mixture)

Concept relating to the uniformity in a substance. A material that is heterogeneous is distinctly nonuniform in one of these qualities.

Homogeneous (Mixture)

Concept relating to the uniformity in a substance. A material that is homogeneous is uniform in composition or character

Chemical

In chemistry, a chemical substance is a form of matter that has constant chemical composition and characteristic properties. It cannot be separated into components by physical separation methods, i.e. without breaking chemical bonds. It can be solid, liquid, gas, or plasma.

Mixture

In chemistry, a mixture is a material system made up of two or more different substances which are mixed but are not combined chemically. A mixture refers to the physical combination of two or more substances on which the identities are retained and are mixed in the form of solutions, suspensions, and colloids.

Gas

Matter in a form that has low density, is easily compressible and expandable, and expands spontaneously when placed in a larger container. Molecules in a gas move freely and are relatively far apart."Vapor" often refers to a gas made of a substance that is usually encountered as a liquid or solid; for example, gaseous H2O is called "water vapor"

Matter

Matter is anything that has mass. Air, water, coffee, fire, human beings, and stars are matter. Light, X-rays, photons, gravitons, information, and love aren't matter.

Plasma Science

Plasma Definition: Plasma is a state of matter where the gas phase is heated until atomic electrons are no longer associated with any particular atomic nucleus. Plasmas are made up of positively charged ions and unbound electrons.

Period

Rows in the periodic table are called periods. For example, all of the elements in the second row are referred to as 'second period elements'. All elements currently known fall in the first seven periods.

Change of State

The process whereby liquid is heated to the point of evaporation changing the liquid into a gas the condensation of a gas on a cooler surface returning it from gaseous to liquid form.

Chemistry

The study of matter and its transformations

Physical Change

a change from one state (solid or liquid or gas) to another without a change in chemical composition

Element

element - Compare with compound and mixture .An element is a substance composed of atoms with identical atomic number . The older definition of element (an element is a pure substance that can't be decomposed chemically) was made obsolete by the discovery of isotopes .

Family

group of things which are related