Fundamentals of Atomic Structure and Composition, Fundamentals of Chemistry and Atomic Structure

Atom

unit of element, composed of protons, electrons and neutrons

Molecule

unit of compounds, composed of elements

Electron

negative part of atom, outside the nucleus, amu = 0

Proton

positive part of atom, inside the nucleus, amu = 1

Neutron

neutral part of atom, inside the nucleus, amu = 1

Nucleus

center of the atom, contains all mass of atom, consists of protons and neutrons

AMU

atomic mass unit, 1/12 the mass of Carbon-12 nucleus

Atomic Number

identifies the element, equal to the number of protons (which = # of electrons)

Mass Number

mass of the nucleus, equal to protons and neutrons (atomic mass rounded to whole #)

Atomic Mass

mass of the atom

Isotope

atom of an element with same atomic # and different mass #; Atom of an element with same # of protons but different # of neutrons

Ion

atom with a charge; charge is due to loss or gain of electrons

Cation

positive ion; lost electrons

Anion

negative ion; gained electrons

Group

vertical columns on periodic table; grouping of elements with similar properties

Period

horizontal rows on periodic table; no similarity in properties

Valence Electrons

# of electrons in outermost energy level; bonding electrons

Law of Constant Composition

A given compound always has the same composition, regardless of where it comes from

Most Abundant Elements on Earth

Oxygen and Silicon are the most prevalent.

Most Abundant Elements in Humans

Oxygen, Carbon, Hydrogen, and Nitrogen are key.

Dalton's Atomic Theory

Five foundational principles explaining atomic behavior.

Incorrect Parts of Dalton's Theory

Two parts of the theory were disproven.

JJ Thomson's Discovery

Identified the electron as a subatomic particle.

William Thomson's Theory

Proposed the existence of a positively charged atom.

Rutherford's Discovery

Discovered the atomic nucleus through gold foil experiment.

Rutherford's Experiment

Demonstrated the nucleus's existence using alpha particles.

Rutherford and Chadwick's Discovery

Identified the neutron as a neutral subatomic particle.

Subatomic Particles

Protons, neutrons, and electrons compose an atom.

Charge of Subatomic Particles

Protons: +1, Neutrons: 0, Electrons: -1.

Isotopes

Atoms with same protons, different neutrons.

Calculating Isotope Particles

Use mass number to find protons, neutrons, electrons.

Ions

Charged atoms; cations are positive, anions are negative.

Periodic Table Groups

Includes alkali metals, alkaline earth metals, transition metals, halogens, noble gases.

Properties of Metals

Conductive, malleable, ductile, shiny appearance.

Properties of Nonmetals

Poor conductors, brittle, various colors and states.

Properties of Metalloids

Exhibit properties of both metals and nonmetals.

Diatomic Atoms

Molecules consisting of two identical atoms.

Liquid Elements

Mercury (Hg) and Bromine (Br) are liquid at room temperature.

Gaseous Elements

Includes H, N, O, F, Cl, and noble gases.

Allotropes

Different forms of the same element, e.g., carbon.

Examples of Carbon Allotropes

Diamond, graphite, and Buckminsterfullerenes.