Chapter 1 & 2: Basic Chemistry, Isotopes, and Chemical Bonds

Vocabulary flashcards reviewing core chemistry concepts from the lecture, including subatomic structure, isotopes, biological imaging, electron shells, and chemical bonding types.

Atom

The basic unit of matter made up of subatomic particles.

Proton

A positively charged subatomic particle located in the nucleus of an atom that determines the atomic number.

Neutron

A subatomic particle located in the nucleus of an atom that carries no electrical charge.

Electron

A negatively charged subatomic particle outside the nucleus with a mass roughly equal to $\frac{1}{2000}$ the weight of the nucleus, which determines the reactive properties of an atom.

Nucleus

The dense central portion of an atom composed of protons and neutrons that accounts for the mass number.

Atomic Number

The number of protons contained in the nucleus of an atom.

Mass Number

The total weight or sum of the protons and neutrons within an atom's nucleus.

Isotope

Atoms of the same element that have the same number of protons but an extra or different number of neutrons, making them heavier.

Radioactive Isotope

An unstable isotope whose energized nucleus breaks down and releases radiation along with subatomic particles to achieve stability.

Carbon-14

A radioactive isotope of carbon present in less than $0.000001\%$ of the body that decays at a constant rate after an organism dies, used to estimate the age of dead organisms up to 10,000 years.

PET Scan

A medical imaging technique that utilizes low levels of radioactive isotopes with short half-lives to trace the location and status of organ function or disease.

Tau Protein

A protein inside brain neurons that, when misfolded, forms tangles, disrupts synapses, and causes brain cells to rupture in Alzheimer's patients.

Beta Amyloid

A misfolded protein that accumulates outside neurons in the brain of an Alzheimer's patient.

Valence Shell

The outermost electron shell of an atom that determines its reactivity and capacity to form chemical bonds.

Inert Gas

An element with a completely full outermost electron shell (such as helium, neon, or argon) that does not participate in chemical reactions.

Octet Rule

The principle stating that atoms are chemically stable when they achieve eight electrons in their outermost electron shell.

Covalent Bond

A chemical bond formed when two atoms share electrons to complete their outer shells and create a stable molecule.

Electronegativity

The degree of affinity or pull an atom exerts toward shared electrons in a chemical bond.

Polar Covalent Bond

A covalent bond formed by unequal sharing of electrons due to high electronegativity in one atom, producing slight positive and negative charges across the molecule.

Nonpolar Covalent Bond

A covalent bond characterized by equal sharing of electrons between atoms, resulting in a symmetrical and uncharged molecule.

Ionic Bond

A strong chemical bond formed by the full transfer of electrons from an electron donor to an electron recipient, creating attraction between oppositely charged ions.

Cation

A positively charged ion formed when an atom donates or gives up an electron.

Anion

A negatively charged ion formed when an atom receives or picks up an electron.

Hydrogen Bond

A weak interaction formed between a slightly positively charged hydrogen atom in a polar molecule and a slightly negatively charged atom of a neighboring polar molecule.