General Chemistry Exam 1

Matter

Everything in the universe that has mass or occupies space.

Energy

The capacity to transfer heat or do work.

Chemistry

The study of composition, structure, and properties of matter.

Homogenous

A mixture that is uniform throughout. (i.e. vinegar)

Heterogenous

A mixture that is NOT uniform throughout. (i.e. salad dressing)

Element

A pure substance that can not be broken down.

Compound

A substance consisting of two or more elements.

Law of Constant Composition

Every sample of a particular compound always contains the same elements in the same proportions.

Atom

The smallest representative particle of an element.

Filtration

A way to separate a substance by using a medium to hold one of the substances back. (i.e. using a sift)

Distillation

Vaporizing volatile components and condensing them.

Intensive Properties

Properties of matter independent of quantity. (i.e. color, malleability, melting temperature)

Extensive Properties

Properties that characterize how much of the object is present. (i.e. length, width, mass, volume)

Physical Properties

Properties of a pure substance that can be observed or measured without changing the substance. (i.e. color)

Density

The ratio of an object's mass to its volume.

Chemical Properties

A property of a substance that can only be observed by reacting it with another substance.

Solid Phase

Definite volume and shape.

Liquid Phase

Definite volume, indefinite shape.

Gas Phase

Indefinite volume and shape.

Sublimation

Changing directly from a solid to a vapor (gas).

Deposition

Changing directly from a gas to a liquid (it was never a solid).

Kelvin Formula

K-273.15= C

Celsius Formula

C= (5/9)(F-32)

Fahrenheit Formula

F= (9/5)(C+32)

Thomson

Proposed new model for the atom through his plum pudding experiment. Discovered the electron.

Nucleus

Positively charged center of the atom that contains most of the mass.

Ion

An atom or group of atoms with a positive or negative charge.

Isotopes

Atoms of an element containing the same amount of protons but a different number of neutrons.

Metals

Type of element that conducts both heat and electricity well. They are also malleable and ductile (can form a wire)

Nonmetals

Type of element that is a poor conductor of both heat and electricity. They are gases at room temperature and most of the solids are brittle.

Metalloids

Physical properties of a metal, chemical properties of a nonmetal.

Ionic Compound

A compound composed of a positive and negative chafed ion held together by electrons.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Polyatomic Ions

Charged groups of two or more atoms joined together by covalent bonds.

atomic number

shows the number of protons=electroms

atomic weight

number below element symbol

atomic weight - atomic number = number of neutrons