AP Chemistry Unit 1 Review Flashcards

AP Chem Unit 1 flashcards

Avogadro's Number

The connection between the number of moles in a pure sample and the number of constituent particles (or formula units) of that substance; 6.022 × 1023 mol-1

The formula n = m/M

n = number of moles, m = mass of the sample, M = molar mass

Mass Spectroscopy

Separates ionized atoms or molecules by changing magnetic field or voltage.

Four steps of Mass Spectroscopy

Ionization, Acceleration, Deflection, Detection

Law of Definite Proportions

A chemical compound always contains the same elements in the exact same proportions by mass.

Empirical Formula

A chemical formula showing the simplest ratio of elements in a compound

Atomic Structure

The atom is composed of negatively charged electrons and a positively charged nucleus that is made of protons and neutrons.

Coulomb's Law

Like charges repel and opposite charges attract, with a force proportional to the product of the charges and inversely proportional to the square of the distance between them.

Core Electrons

Inner electrons.

Valence Electrons

Outer electrons.

Effective Nuclear Charge Formula

Zeff = Z – S, where Z is the atomic number and S is the number of shielding electrons.

Photoelectron Spectroscopy (PES)

An experimental technique that measures the relative energies of electrons in atoms and molecules based on the photoelectric effect

Photoelectric Effect

The emission, or ejection, of electrons from the surface of, generally, a metal in response to incident light.

PES Peak Position

The position of the peak along the x-axis indicates the relative energy needed to remove a specific electron from an atom. A greater binding energy = electrons are closer to the nucleus

PES Peak Height

The height of the peak corresponds to the relative number of electrons in that energy level and sublevel

Ionization Energy

The energy required to remove an electron from an atom

Electron Affinity

The amount of energy released when an electron is added to a neutral atom

Electronegativity

Shows how well an atom can attract electrons towards itself