Atomic Bonding and Structure - Vocabulary Flashcards (ENGLISH)

Vocabulary flashcards covering key terms from the lecture notes on atomic structure, isotopes, covalent and ionic bonding, and molecular shapes.

Atomic number

The number of protons in an atom's nucleus; determines the identity of the element and equals the number of electrons in a neutral atom.

Mass number

The total number of protons and neutrons in an atom's nucleus.

Proton

A positively charged subatomic particle located in the nucleus; mass about 1 amu.

Neutron

A neutral subatomic particle located in the nucleus; mass about 1 amu.

Electron

A negatively charged subatomic particle that orbits the nucleus in electron shells; mass 0.

Isotope

Atoms of the same element (same atomic number) with different numbers of neutrons and thus different mass numbers.

Nuclide notation

A notation showing atomic number and mass number (and charge) of atoms/ions to determine protons, electrons and neutrons. Example: ²³₁₁Na

Relative atomic mass (RAM)

The average mass of an element's atoms taking into account the abundance of its isotopes.

Isotopic abundance

The percentage of each isotope of an element found in a natural sample.

Covalent bond

A bond between two atoms where two positive nuclei are held together by electrostatic attraction to shared pair of electrons.

Covalent molecular substance

A substance composed of discrete molecules held together by weak intermolecular forces and with low melting/boiling points. Can be gas, liquid or solid at room temperature. Does not conduct electricity.

Covalent network substance

A substance with a giant network of covalent bonds throughout the material; very high melting/boiling points. Does not conduct electricity (except graphite). All solids at room temperture.

Double bond

A covalent bond involving two shared pairs of electrons between atoms.

Triple bond

A covalent bond involving three shared pairs of electrons between atoms.

Diatomic molecule

A molecule consisting of two atoms (e.g., H2, N2, O2, F2, Cl2, Br2, I2).

Ionic bond

The electrostatic attraction between oppositely charged ions in an ionic compound.

Ionic lattice

A regular, repeating arrangement of alternating positive and negative ions in a solid.

Periodic table

A tabular arrangement of elements in order of increasing atomic number, showing groups and periods and periodic trends.

Group (periodic table)

A vertical column in the periodic table; elements in a group have similar outer electron counts and similar chemical properties.

Period (periodic table)

A horizontal row in the periodic table; indicates the number of electron shells in elements of that row.

Valence electrons

Electrons in the outermost shell of an atom; determine bonding behaviour and usually equal the group number.

Noble gases

Group of elements that are monatomic with full outer electron shells and very low reactivity.

Electron shells

Discrete energy levels around the nucleus where electrons reside; the outermost shell is the valence shell.