Summary of Introduction to Chemistry & Bonds - Vocabulary Flashcards

Vocabulary flashcards covering key concepts from the notes: energy, matter and elements, atomic structure, isotopes, bonds, water polarity, and radiation.

First Law of Thermodynamics

Energy cannot be created or destroyed; it can only be transferred or transformed (energy is conserved).

Major Body Elements

The six elements that make up about 98% of the human body: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphate.

Isotopes

Atoms of the same element with varying numbers of neutrons; some are radioactive and can be dangerous or carcinogenic.

Atomic Structure

Atoms consist of a nucleus containing protons and neutrons, with electrons orbiting; the arrangement determines element properties.

Proton

Positively charged subatomic particle in the nucleus.

Neutron

Electrically neutral subatomic particle in the nucleus.

Electron

Negatively charged subatomic particle that orbits the nucleus.

Nucleus

Central core of the atom containing protons and neutrons.

Valence Shell

Outermost electron shell; full valence shell is inert; incomplete valence shell is reactive.

Ionic Bond

Bond formed by transfer of electrons; donor becomes a cation (+), acceptor becomes an anion (-); e.g., NaCl.

Covalent Bond

Bond formed by sharing electrons; can be nonpolar (equal sharing) or polar (unequal sharing).

Nonpolar Covalent Bond

Covalent bond with equal sharing of electrons (e.g., methane).

Polar Covalent Bond

Covalent bond with unequal sharing of electrons, creating partial charges (e.g., water).

Water Polarity

Water's polarity arises from oxygen's high electronegativity; the oxygen end is negative, hydrogen ends are positive.

Hydrogen Isotopes

Protium (no neutron), Deuterium (1 neutron), Tritium (2 neutrons).

Atomic Number

The number of protons in the nucleus; defines the element's identity.

Atomic Mass

Approximate mass of an atom; mainly the sum of protons and neutrons; electrons contribute negligible mass.

Mass Number

Sum of protons and neutrons in the nucleus.

Isotope (Revisited)

Isotopes have the same number of protons but different numbers of neutrons.

Radioactive Isotope (Radioisotope)

Unstable isotope that decays and emits radiation; health effects depend on exposure.

Mutagen

Mutagenic agents cause DNA mutations.

Carcinogen

Carcinogenic agents can cause cancer with long-term exposure.

Gamma Radiation

Gamma radiation has the highest energy; the most dangerous form of radiation.

X-rays

Ionizing radiation; protective measures are required (e.g., walls, shielding).

Alpha Radiation

Lower energy radiation; alpha particles are used in smoke detectors; everyday exposure to alpha is common.

Molecule

Two identical atoms bonded together (e.g., O2).

Compound

Two different atoms bonded together (e.g., H2O).

Water as Molecule & Compound

Water (H2O) is both a molecule and a compound.

Neon

Noble gas that is inert due to a full valence shell.

Oxygen Electronegativity & Water Polarity

Oxygen's high electronegativity creates polarity in bonds; the oxygen end is negative, hydrogens are positive.