Atomic Structure & Intermolecular Forces Study Guide

This set of flashcards covers key vocabulary from the Atomic Structure & Intermolecular Forces lecture notes, essential for exam preparation.

Matter

Composed of atoms, which are fundamental building blocks.

Atoms

The smallest distinguishable part of an element, unique by the number of protons.

Atomic Models

Representations of atoms that evolve with evidence, used for different purposes (e.g., Dalton, Thomson, Rutherford, Bohr, Quantum).

Scientific Theory

A well-supported explanation based on evidence, distinct from an everyday guess.

Electrostatic Forces

Attractions or repulsions between atoms/molecules due to charges, stronger than gravity.

Attractions

Lower the potential energy of a system.

Repulsions

Raise the potential energy of a system.

Stable Systems

Form where attractions equal repulsions, often represented by the dip in an energy diagram.

Phase Change Temperature

Depends on the strength of intermolecular forces; stronger forces lead to higher melting/boiling points.

Dalton's Theory

Proposed that matter is made of indivisible atoms, atoms of an element are identical, and compounds are combinations of atoms.

Thomson's Cathode Ray Tube Experiment

Led to the discovery of electrons, showing atoms contain negative particles.

Rutherford's Gold Foil Experiment

Demonstrated the existence of a dense, positively charged nucleus within an atom.

London Dispersion Forces (LDF)

Weak, temporary attractive forces present in all molecules due to instantaneous dipoles, stronger in larger atoms/molecules.

Covalent Bonds

Strong bonds formed by the sharing of electrons between atoms within a molecule.

Atomic Number (Z)

The number of protons in an atom, which determines the element and is found on the periodic table.

Isotopes

Atoms of the same element (same number of protons) but with different numbers of neutrons.

Nucleus

The central part of an atom, containing protons (positive) and neutrons (neutral).

Electrons

Negatively charged subatomic particles that reside in orbitals or clouds around the nucleus.

Potential Energy (PE)

Stored energy due to the position or arrangement of particles, related to attractions and repulsions.

Kinetic Energy (KE)

Energy of motion; particles move faster as KE increases.

Energy Diagrams

Graphs that show the relationship between potential energy and internuclear distance between atoms.

Gas

A state of matter where particles are far apart and move freely.

Liquid

A state of matter where particles are closer together but can flow past each other.

Solid

A state of matter where particles are tightly packed and vibrate in fixed positions.

Scientific Method

A systematic approach to scientific inquiry involving observation, hypothesis, experimentation, data analysis, and conclusion.

Hypothesis

A testable prediction or explanation for an observation.

Law

A description of a relationship or phenomenon, often mathematical (e.g., F=ma), but does not explain why.

Molecule

Two or more atoms bonded together.

Compound

A molecule formed from two or more different elements chemically bonded together.