Unit 1 Gen Chem

Atom

the smallest particle of an element that cannot be chemically or mechanically divided into smaller particles

Scientific theory

a concise, extensively tested explanation of widely observed natural phenomena

Element

a pure substance that cannot be separated into simpler substances

Compound

a pure substance composed of two or more elements that are chemically bonded in fixed proportion

Scientific methods

approaches to acquiring knowledge by observing phenomena, developing a testable hypothesis, and carrying out additional experiments that test the validity of the hypothesis

Scientific law

a concise and generally applicable statement of a fundamental scientific principle

law of definite proportions

the principle that a compound always contains the same proportion of its component elements

law of constant composition

the principle that all samples of a given compound have the same elemental composition

hypothesis

a tentative and testable explanation for an observation or a series of observations

law of multiple proportions

the principle that, when two masses of one element react with a given mass of another element to form two compounds, the two masses of the first element have a ratio of two small whole numbers

chemical formula

a notation that uses the symbols of the elements to represent the elemental composition of a pure substance; subscripts indicate the relative number of atoms of each element in the substance

Covalent Bond

A chemical bond formed by the sharing of electron pairs between atoms.

Ionic bond

A chemical bond formed through the attraction between oppositely charged ions(metal&nonmetal), typically involving the transfer of electrons from one atom to another.

Heterogenous Mixture

A mixture consisting of visibly different substances or phases, where the components are not uniformly distributed.

Homogenous Mixture

A mixture that has a uniform composition and appearance throughout, with components that are evenly distributed.