General Chemistry 1 – Atoms, Isotopes & Chemical Nomenclature

Vocabulary flashcards summarizing key terms from the lecture on atomic structure, isotopes, periodic trends, bonding types and chemical formula conventions.

Atom

Smallest unit of an element; composed of protons, neutrons and electrons.

Proton

Positively charged sub-atomic particle found in an atom’s nucleus.

Neutron

Electrically neutral sub-atomic particle located in the nucleus.

Electron

Negatively charged sub-atomic particle that orbits the nucleus.

Atomic Number

Number of protons (and, in a neutral atom, electrons) in an element.

Atomic Mass

Sum of protons and neutrons in an atom’s nucleus.

Isotope

Atoms of the same element with identical proton counts but different neutron numbers (same atomic number, different atomic mass).

Protium

Hydrogen-1 isotope (1 p, 0 n); used to treat stomach and intestinal acid disorders.

Deuterium

Hydrogen-2 isotope (1 p, 1 n); slows neutrons in heavy-water reactors and acts as a tracer in fusion research.

Tritium

Hydrogen-3 isotope (1 p, 2 n); radioactive tracer in biochemical and groundwater studies.

Average Atomic Mass

Weighted average of an element’s isotopic masses based on natural abundance.

Periodic Table of Elements

Tabular arrangement of elements by increasing atomic number and recurring chemical properties.

Alkali Metals (Group 1)

Highly reactive metals in the first column (excluding hydrogen).

Alkaline Earth Metals (Group 2)

Second-column metals, reactive but less so than alkali metals.

Transition Metals (Groups 3-12)

Metals in the table’s center that often form colored ions and multiple oxidation states.

Boron Group (Group 13)

Family of elements headed by boron.

Carbon Group (Group 14)

Family containing carbon, silicon, etc.

Nitrogen Group (Group 15)

Family containing nitrogen, phosphorus, etc.

Oxygen Group (Group 16)

Family containing oxygen, sulfur, etc.

Halogens (Group 17)

Very reactive non-metals that form salts with metals.

Noble Gases (Group 18)

Extremely unreactive gases with full valence shells.

Metal

Element that conducts heat/electricity well, is malleable and ductile; usually solid and shiny.

Non-metal

Element that poorly conducts heat/electricity and lacks malleability and ductility; many are gases.

Metalloid

Element with intermediate properties; can behave as a semiconductor.

Semiconductor

Material (often silicon or germanium) whose conductivity can be controlled; vital in electronics and solar panels.

Chemical Formula

Notation showing the elements in a compound and their atom ratios via subscripts.

Ionic Bonding

Electrostatic attraction between cations and anions (metal + non-metal).

Covalent Bonding

Attraction resulting from shared electron pairs between non-metals.

Cation

Positively charged ion, typically formed by a metal losing electrons.

Anion

Negatively charged ion, typically formed by a non-metal gaining electrons.

Oxidation State

Apparent charge of an atom in a compound; used for balancing formulas and naming transition-metal compounds.

Polyatomic Ion

Covalently bonded group of atoms carrying an overall charge (e.g., SO₄²⁻, NH₄⁺).

Hydroxide Ion

OH⁻; common polyatomic anion found in bases and many ionic compounds.