Chemistry 221 L1 Video Lecture from October 3, 2025. This video covers material from Chapter 2 and Chapter 3 including the molar mass of compounds, light and electromagnetic radiation, frequency, wavelength, the speed of light, Planck’s constant, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from October 2, 2025, Part 4 of 4. This video covers material from Chapter 3 including the Bohr model for the atom, sharp line spectra, absorbance and emission, calculating the wavelength and frequency from a change in energy, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from October 2, 2025, Part 3 of 4. This video covers material from Chapter 3 including a discussion of light, electromagnetic radiation, frequency and wavelength, the speed of light and Planck’s constant and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from October 2, 2025, Part 2 of 4. This video covers material from Chapter 2 including a discussion of the mole and Avogadro’s number, the importance of the atomic mass number with relationship to molar mass, calculating the molar mass of a compound, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from October 2, 2025, Part 1 of 4. This video covers material from Chapter 2 including an overview of the atom, protons, neutrons, electrons, the atomic number, the mass number, isotopes, atomic mass, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L1 Video Lecture from October 1, 2025. This video covers material from Chapter 2 including the importance of atomic mass, how atomic mass is calculated, the 7 diatomics, molecular formulas and empirical formulas, the mole, Avogadro’s number, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L1 Video Lecture from September 29, 2025. This video covers material from Chapter 2 including the composition of the atom (protons, neutrons and electrons), the atomic number, the Rutherford Gold Foil experiment, atomic mass, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L1 Video Lecture from September 26, 2025. This video covers material from Chapter 1 (and a small bit from Chapter 2) including measurements in chemistry, precision and accuracy significant figures, rounding of numbers, mass percentages, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from September 25, 2025, Part 3 of 3. This video covers material from Chapter 1 including measurements in chemistry, precision and accuracy significant figures, rounding of numbers, mass percentages, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from September 25, 2025, Part 2 of 3. This video covers material from Chapter 1 including more on elements and the periodic table, SI units, temperature scales, density, dimensional analysis, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L2 Video Lecture from September 25, 2025, Part 1 of 3. This video covers material from Chapter 1 including a discussion of “what is chemistry”, types of chemistry, the importance of chemistry, atoms, molecules and mixtures, the periodic table, important groups on the periodic table, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L1 Video Lecture from September 24, 2025. This video covers material from Chapter 1 including a discussion of measurements and SI units, length, mass, volume, density, temperature scales, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Chemistry 221 L1 Video Lecture from September 22, 2025. This video covers material from Chapter 1 including a discussion of “what is chemistry”, types of chemistry, the importance of chemistry, atoms, molecules and mixtures, and more. CH 221 website: http://mhchem.org/221 Let me know if you have any questions! Peace!

Welcome! This is a video to help students get started in Dr. Russell’s chemistry classes at Mt. Hood Community College in Gresham, Oregon, USA. Website: http://mhchem.org Let me know if you have any questions! Peace!

This video will help you find our three main chemistry classrooms (namely AC 1303, AC 2501 and AC 2507) as well as my office (AC 2568) at Mt. Hood Community College in Gresham, Oregon, USA. To get to all of these locations, go to the “F” or “G” parking lots (or as close to them as possible), both of which are located near the main MHCC entrance on NE 29th street and NE Kane Dr. in Gresham ). AC 1303 is on the lower level of the campus, adjacent to the Planetarium. AC 2501, AC 2507 and my office (AC 2568) are located on the upper level of campus, and all are very close to the “F” and “G” parking lots. Let me know if you have any questions! Peace!

Welcome to Chemistry 221 with Dr. Michael Russell!

This the Complete Lecture for Chapter 2. This episode is part 2 of 2 episodes.

This the Complete Lecture for Chapter 2. This episode is part 1 of 2 episodes.

A screencast from Chapter 2 in CH 221 entitled “The Mole and Molar Mass”

A screencast from Chapter 2 in CH 221 entitled “Empirical Formulas and Isomers”