SCIENCE 8 REVIEWER Q2

These flashcards cover key concepts regarding atomic theory, atomic models, periodic table, and quantum numbers.

Democritus

Introduced the word 'Atomos', meaning very small indivisible objects.

Atomos

The term used by Democritus to describe very small indivisible objects.

Aristotle's belief

Matter is made of natural elements: air, fire, earth, water.

John Dalton's Atomic Theory

Proposed the first atomic theory and introduced the Solid Sphere Model.

Solid Sphere Model

Atoms are tiny, indivisible particles where atoms of an element are all the same.

Plum Pudding Model

Proposed by J.J. Thompson, where electrons are embedded within a positively charged 'pudding'.

Cathode Ray Tube Experiment

Led to J.J. Thompson's discovery of electrons.

Nuclear Model

Proposed by Ernest Rutherford, revealing the existence of the nucleus.

Gold Foil Experiment

Led to the discovery that atoms have a nucleus.

Proton

A positively charged particle discovered by Ernest Rutherford.

Planetary Model

Proposed by Niels Bohr, suggesting electrons move around the nucleus in fixed orbits.

Quantum Model

Introduced by Erwin Schrodinger, explaining electrons exist in wave-like patterns.

Atom

The smallest particle of matter made up of protons, neutrons, and electrons.

Nuclear Strong Force

Holds protons and neutrons together within the nucleus.

Subatomic Particles

The components of an atom: electrons, protons, and neutrons.

Electron

A negatively charged subatomic particle, discovered by J.J. Thompson.

Proton

A positively charged subatomic particle discovered by Ernest Rutherford.

Neutron

A neutral subatomic particle discovered by James Chadwick.

Atomic Number (Z)

Equivalent to the number of protons in an atom.

Mass Number (A)

The total number of protons and neutrons in an atom.

Mass Number Formula

Mass No. = Protons + Neutrons.

Anion

A negatively charged ion that gains electrons.

Cation

A positively charged ion that loses electrons.

Electron Configuration

The arrangement of electrons in an atom's energy levels.

Electron Cloud

The region where electrons can be found around the nucleus.

Atomic Orbital

Region in space where there is a high probability of finding electrons.

Principal Quantum Number (n)

Describes the main energy level of an electron in an atom.

Angular Momentum Quantum Number (l)

Specifies the shape of an orbital.

Magnetic Quantum Number (mℓ)

Describes the orientation of an orbital in space.

Spin Quantum Number (ms)

Indicates the spin direction of an electron in an orbital.

Pauli Exclusion Principle

States that no two electrons can occupy the same orbital with the same spin.

Hund’s Rule

Every orbital in a subshell gets one electron before any gets a second.

Aufbau Principle

Electrons occupy the lowest energy orbitals first.

Periodic Table of Elements

A systematic way of organizing and classifying elements.

Groups

Columns in the periodic table that indicate elements with similar properties.

Periods

Rows in the periodic table that represent increasing atomic numbers.

Valence Electrons

Electrons in the outermost shell that determine chemical properties.

Periodic Trends

Patterns observed in the periodic table such as atomic radius and ionization energy.

Atomic Radius

The distance from the nucleus to the outermost shell of an electron.

Increasing Atomic Radius Trends

Atomic radius generally increases down a group in the periodic table.

Ionic Radius

The radius of an atom's ion.

Increasing Metallic Character

The trend where metallic character increases as you move down a group.

Electronegativity

The tendency of an atom to attract electrons in a bond.

Ionization Energy

The energy required to remove an electron from an atom.

Electron Affinity

The change in energy when an electron is added to an atom.

Johann Dobereiner

Grouped elements into triads based on similar properties.

Law of Octaves

Arranged elements by atomic weight with similar properties.

Dmitri Mendeleev

Created the first periodic table, arranging 60 known elements by atomic mass.

Henry Moseley

Determined the atomic number and rearranged the periodic table accordingly.

Glenn Seaborg

Synthesized transuranic elements and contributed to the actinide series.

Natural Elements

Elements that occur naturally in nature.

Synthetic Elements

Elements that are artificially created in laboratories.

Element Classification

Elements are classified into metals, nonmetals, and metalloids.

s subshell

The subshell with l=0 and can hold a maximum of 2 electrons.

p subshell

The subshell with l=1 and can hold a maximum of 6 electrons.

d subshell

The subshell with l=2 and can hold a maximum of 10 electrons.

f subshell

The subshell with l=3 and can hold a maximum of 14 electrons.

Group 1 Elements

Alkali metals, which have one valence electron.

Group 2 Elements

Alkaline earth metals, with two valence electrons.

Transition Metals

Elements found in groups 3-12 that have varying valence electrons.

Lanthanides

Fifteen elements from cerium (Ce) to lutetium (Lu), typically f-block elements.

Actinides

Fifteen elements from actinium (Ac) to lawrencium (Lr), typically f-block elements.