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UNIT 1: ATOMIC STRUCTURE & PROPERTIES

The periodic table gives you basic but important information about each element

Example of information provided by the period table. The top left is the atomic number, C is the symbol, and 12.011 is the atomic/molar mass.

Symbol - The unique symbol that represents an element on the periodic table

Atomic Number - The number of protons located within the nucleus of an element. Also equal to the number of electrons surrounding the nucleus of a neutrally charged element.

Molar Mass - The average atomic mass of an atom and also the average mass per mol of the atom

Periods - the horizontal rows of the periodic table

Groups - the vertical columns of the periodic table

GROUP(S)

NAME

1

Alkali Metals

2

Alkaline Earth Metals

3-12

Transition Metals

17

Halogens

18

Noble Gases

The two rows offset beneath the table are alternatively called the Lanthanides (4f) and the Actinides (5f): Rare Earth Metals or Inner Transition Metals.

Mass Number - The sum of an atoms protons and neutrons

Isotopes - Atoms of an element with different number of neutrons

Avogadro’s Number - The number of atoms that are in a single mole of any given element (6.022 x 10^23 particles)

Molarity(M) - moles of solute/liters of solution

Empirical Formula - The simplest ratio of one element to another in a compound

Molecular Formula - The actual formula for a substance

Electrostatic Force - the attraction between opposite charges

Coulomb’s Law - Force of attraction = q1q2/r^2. Measures the force of attraction between two charges.

Energy Level - fixed distances from the nucleus of an atom where electrons may be found (1-7)

Subshells - a subdivision of electron shells separated by orbitals (s, p, d, & f)

Orbital - the position surrounding an atom’s nucleus where electrons are most likely to be found at any given moment

Electron Configuration - the complete description of the energy level and subshell that each electron on an element inhabits

Aufbau Principle - when building up the electron configuration of an atom, electrons are placed in orbitals, subshells, and shells in order of increasing energy

Pauli Exclusion Principle - two electrons which share an orbital cannot have the same spin

Hund’s Rule - when an electron is added to a subshell, it will always occupy an empty orbital if one is available

Valence Electrons - the electrons in the outermost s and p subshells

Atomic Radius - the approximate distance from the nucleus of an atom to its valence electrons

Ionization Energy - the energy required to remove an electron from an atom

Electronegativity - how strongly the nucleus of an atom attracts the electrons of other atoms in a bond

Electron Affinity - the energy change that occurs when an electron is added to an atom in its gaseous state

Effective Nuclear Charge - the net attractive force of the nucleus on any given electron (approximately equal to the number of protons - core electrons)

UNIT 1: ATOMIC STRUCTURE & PROPERTIES

The periodic table gives you basic but important information about each element

Example of information provided by the period table. The top left is the atomic number, C is the symbol, and 12.011 is the atomic/molar mass.

Symbol - The unique symbol that represents an element on the periodic table

Atomic Number - The number of protons located within the nucleus of an element. Also equal to the number of electrons surrounding the nucleus of a neutrally charged element.

Molar Mass - The average atomic mass of an atom and also the average mass per mol of the atom

Periods - the horizontal rows of the periodic table

Groups - the vertical columns of the periodic table

GROUP(S)

NAME

1

Alkali Metals

2

Alkaline Earth Metals

3-12

Transition Metals

17

Halogens

18

Noble Gases

The two rows offset beneath the table are alternatively called the Lanthanides (4f) and the Actinides (5f): Rare Earth Metals or Inner Transition Metals.

Mass Number - The sum of an atoms protons and neutrons

Isotopes - Atoms of an element with different number of neutrons

Avogadro’s Number - The number of atoms that are in a single mole of any given element (6.022 x 10^23 particles)

Molarity(M) - moles of solute/liters of solution

Empirical Formula - The simplest ratio of one element to another in a compound

Molecular Formula - The actual formula for a substance

Electrostatic Force - the attraction between opposite charges

Coulomb’s Law - Force of attraction = q1q2/r^2. Measures the force of attraction between two charges.

Energy Level - fixed distances from the nucleus of an atom where electrons may be found (1-7)

Subshells - a subdivision of electron shells separated by orbitals (s, p, d, & f)

Orbital - the position surrounding an atom’s nucleus where electrons are most likely to be found at any given moment

Electron Configuration - the complete description of the energy level and subshell that each electron on an element inhabits

Aufbau Principle - when building up the electron configuration of an atom, electrons are placed in orbitals, subshells, and shells in order of increasing energy

Pauli Exclusion Principle - two electrons which share an orbital cannot have the same spin

Hund’s Rule - when an electron is added to a subshell, it will always occupy an empty orbital if one is available

Valence Electrons - the electrons in the outermost s and p subshells

Atomic Radius - the approximate distance from the nucleus of an atom to its valence electrons

Ionization Energy - the energy required to remove an electron from an atom

Electronegativity - how strongly the nucleus of an atom attracts the electrons of other atoms in a bond

Electron Affinity - the energy change that occurs when an electron is added to an atom in its gaseous state

Effective Nuclear Charge - the net attractive force of the nucleus on any given electron (approximately equal to the number of protons - core electrons)