GE-Chem Lab: Quiz 1 (Lesson 1)

Matter - anything that occupies space and has mass

Atoms - they compose matter

Atoms - smallest identifiable unit of an element

Leucippus and Democritus - they theorized that matter was ultimately composed of small, indivisible particles

Democritus - he coined the term “atomos”

Antoine Lavoisier - he established the “Law of Conservation of Mass”

Law of Conservation of Mass - “In a chemical reaction, matter cannot be created or destroyed, only rearranged.“

Joseph Proust - he proposed the “Law of Definite Proportions”

Law of Definite Proportions - “Different samples of the same element always contain its constituent elements in the same proportion by mass.”

John Dalton - he formalized the Atomic Theory

Wilhelm Rontgen - he discovered a type of radiation which he termed X-ray when he was studying vacuum tubes and cathode rays

Henri Becquerel - he discovered the spontaneous emission of radiation from Uranium ores

Marie Curie - she coined the term “radioactivity” for the observed spontaneous radiation

Joseph John Thomson - he discovered the first subatomic particle—electrons, by investigating cathode rays in a vacuum tube

Ernest Rutherford - he demonstrated that there were at least two distinct types of radiation

Alpha and beta radiation - two distinct types of radiation

Hans Geiger - he was Rutherford’s associate in which they proved that α particles are He 2+ ions.

1927 Solvay Conference - the birth of Quantum Mechanics

Max Planck - he proposed the quantization of energy of light to produce a practical solution to the unexplained Blackbody radiation

Albert Einstein - he provided the theoretical background for the Photoelectric Effect

Photoelectric Effect - a phenomenon where electrons are emitted from a plate when exposed to light

Robert Millikan - he succeeded in precisely determining the magnitude of the electron’s charge

Ernest Rutherford, Hans Geiger, and Ernest Marsden - they used α particles to bombard very thin gold foils and discovered protons

James Chadwick - he discovered neutrons

Protons - positive charge

Electrons - negative charge

Neutrons - no charge

Unified atomic mass - defined as 1/12 of the mass of a carbon atom containing 6 protons and 6 neutrons

Nucleus - location of protons and neutrons

Nucleus - dense core of the atom

Nucleus - location of most of the atom’s mass

Electron cloud - location of electrons

Electron cloud - comprises most of the atom’s volume

Electron cloud - mostly an empty space

Element - a pure substance that cannot be broken down into simpler substances by a chemical reaction

Atomic number - it states the number of protons of an element

Z - symbol for atomic number

Julius Lothar Meyer - he created the Periodic Table of Elements similar to Dmitri Mendeleev’s work

Clemens Winkler - discovered eka-silicon

Eka-silicon - modernly known as Germanium

Alkali metals - soft and shiny metals with low melting points

Alkaline earth metals - good conductors of heat and electricity, as well as reacts with water to form basic solutions

Halogens - very reactive and exist as two atoms joined together

Noble gases - very stable and rarely combine with other elements

Isotopes - the term for atoms with the same number of protons but different numbers of neutrons

Werner Heisenberg - a German physicist who formulated the Quantum Theory

Schrodinger equation - a wave equation formulated by Erwin Schrodinger to describe the electronic structure of atoms

Quantum Numbers - numerical labels used to describe the most probable location of electrons in an atom

s-orbital - has a spherical shape

p-orbital - has a dumbbell shape

Electron configuration - shows how the electrons are arranged in an atom’s orbitals

Ground state - the lowest energy arrangement

Aufbau Principle - “As protons are added one by one to the nucleus to build up the elements, electrons are similarly added to the atomic orbitals.

Pauli Exclusion Principle - “No two electrons can be/have the same set of four quantum numbers”

Hunds Rule - “The most stable arrangement of electrons in subshells is one with the greatest number of parallel spins”

Valence electrons - electrons in the outermost shell

Valence shell - it is the outermost shell

Periodic trends - specific patterns that are present in the periodic table that illustrate different aspects of a certain element

Atomic radius - one-half the distance between the two nuclei in two adjacent atoms

Ionic radius - radius of a cation or anion

Ionization energy - the energy required to remove the most loosely held electron from an atom in the gaseous state

Electron affinity - the energy change that occurs when an electron is accepted by an atom in the gaseous state