Chapter 2 - Elements and the Periodic Table Flashcards
Alkali Metals
Group 1 on the Periodic Table (Block S). Properties include: highly reactive, malleable, ductile, good conductors, softer than most metals. Reactivity increases as period number increases; form cations with a 1+ charge.
Alkaline Earths
Group 2 on the Periodic Table (Block S). Properties include: highly reactive, malleable, ductile, good conductors. Reactivity increases as period number increases; form cations with a 2+ charge.
Anion
A negative ion (has more electrons than protons).
Cation
A positive ion (has more protons than electrons).
Transition Metals
Groups 3-12 on the Periodic Table (Block D). Can put more than 8 electrons in their second most outer shell due to the Aufbau Principle. Colourful!
Halogens
Group 17 on the Periodic Table (Block P). Properties include: highly reactive, not found naturally (instead as salts). Reactivity decreases as period number increases; form anions with a 1- charge.
Noble Gases
Group 18 on the Periodic Table (Block S for hydrogen; Block P for all others). Properties include: colourless, full outer shells, found naturally in the atmosphere, very stable, don’t react. Density increases as row number increases; don’t form ions.
Atom
The fundamental building block of all matter.
Atomic Number
The number of protons in the nucleus of an atom; determines the type of atom.
Atomic Symbol
One or two letters used to represent a particular element.
Atomic Mass
The sum of an atom’s protons and neutrons.
Valence Electrons
Electrons that are in an atom’s outer shell.
Electron
A subatomic particle with a negative charge; found in orbitals around the nucleus.
Electron Configuration
The distribution of electrons within an atom’s subshells and orbitals.
Element
A substance made of only one type of atom.
Group
A column on the Periodic Table, which determines the number of electrons in an atom’s outer shell.
Ion
An atom that has lost or gained electrons, giving it a positive or negative charge.
Neutron
A subatomic particle with no charge; found in the nucleus of atoms.
Nucleus
The centre of an atom, containing protons and neutrons.
Period
A row on the Periodic Table, which determines the number of electron shells an atom has.
Periodic Table
A table created by Dmitri Mendeleev that displays elements, their atomic symbol, mass, number, and groups similar elements together.
Proton
A subatomic particle with a positive charge; found in the nucleus of atoms.
Subatomic Particles
Structures that make up atoms; either protons, neutrons or electrons.
Isotopes
An atom that has a different number of protons to neutrons.
Reactivity/Valency
The measure of how readily/easily a substance undergoes a chemical reaction.
Electronegativity
The measure of how firmly an atom is able to hold onto its valence electrons.
Electrostatic Attraction
The bonds between charged particles, such as a positive cation and negative anion.
Balmer Series
The visible light energy emitted from a hydrogen atom when electrons fall to n = 2.
Paschen Series
The infrared radiation emitted by a hydrogen atom when electrons fall to n = 3.
Lyman Series
The ultraviolet radiation emitted by a hydrogen atom when electrons fall to n = 1 (the ground state).
Uncertainty Principle
A theory proposed by Werner Heisenberg, which states that the location of an electron cannot be known, only the probability of it being there.
Wave-Particle Duality
When a quantum - such as an electron or light - can exist as both a wave and a particle. (Note: quantum = specific amount of something).
Orbital
The region of space around an atom where an electron is most likely to exist. Can contain a maximum of 2 electrons.
Shell
The main energy levels in an atom.
Sub-Shell
Smaller energy levels within the main energy levels of an atom. s, p, d & f.
Aufbau Principle
A rule which states that electrons fill lower energy subshells before higher energy subshells.
Compound
A substance that contains more than one type of atom.
Nucleons
Protons and neutrons referred to collectively.
Bohr Model
An atomic theory created by Niels Bohr, which states that:
* Electrons move in fixed orbits called ‘shells’.
* Each shell corresponds to a specific energy level.
* Electrons cannot exist between energy levels.
* Electrons can move between energy levels.
* Orbits of larger radii have higher energy.
Ground State
The lowest energy level of an atom (n = 1).
Schrodinger Model
An atomic theory created by Erwin Schrondiger, which states that:
* electrons behave like waves
* elections are elusive
* orbitals are the regions of space were electrons could be found
* there are subshells within each shell
First Ionisation Energy
The measure of how much energy is required to remove the first electron in an atom.
Block (Periodic Table)
One of the four main areas on the periodic table, which have their valence electrons in the same subshell.
