Curated Video
Electron Withdrawal (-M): The Nitrobenzene Effect
The -M effect involves electron withdrawal through resonance. In nitrobenzene, the nitro group pulls electron density away from the benzene ring, decreasing electron density and making the ring less reactive in electrophilic substitution...
Curated Video
Mesomeric Effect (+M): How Phenol Releases Electrons
The +M effect refers to electron donation through resonance, as seen in phenol where the hydroxyl group donates electrons into the benzene ring. This increases electron density in the ring and impacts reactivity and acidity
Curated Video
Conditions for Resonance: Why Acetamide and Carbonate Matter
Resonance requires specific conditions for electron delocalization. The molecule must have a conjugated system with alternating single and double bonds, and atoms must be capable of sharing electrons. Acetamide and the carbonate ion are...
Curated Video
Resonance in Action: Bond Length, Acidity & More!
Resonance has far-reaching effects on molecular properties. It can equalize bond lengths, making double bonds longer and single bonds shorter than expected. It also stabilizes charged species, influencing acidity and basicity. For...
Curated Video
Pi-n Conjugation: Unlocking the Secrets of Molecular Stability
Pi-n conjugation occurs when a lone pair of electrons (n) interacts with a pi system, enhancing electron delocalization. This conjugation stabilizes the molecule, as the lone pair contributes to the overall resonance. Pi-n conjugation...
Curated Video
Conjugated Systems: Where Resonance Comes to Life
Conjugated systems consist of alternating single and double bonds, which enable the delocalization of pi electrons over multiple atoms. This delocalization stabilizes the molecule and can affect properties like bond length, reactivity,...
Curated Video
Resonance in Chemistry: The Dance of Electrons
Resonance is a concept used to describe delocalization of electrons in a molecule across multiple atoms. In resonance structures, electrons are shared between atoms in ways that stabilize the molecule. This "electron dance" can lower the...
Curated Video
Resonance (Chemistry) Explained in Simple Words with Examples
Resonance is a way of describing delocalized electrons within certain molecules where a single Lewis formula cannot express the bonding. To understand resonance in chemistry, you need to first understand covalent bonds, sigma and pi...
The Business Professor
Six Leadership Styles
Six Leadership Styles. According to Daniel Goleman, Richard Boyatzis, and Annie McKee, there are six emotional leadership styles – Authoritative, Coaching, Affiliative, Democratic, pacesetting
Curated Video
Shepherding, Gravitationally
Astrophysicist Scott Tremaine (Institute for Advanced Study) describes his experiences at developing our understanding of "shepherding moons" and how it related to the rings of Saturn and Uranus.
Flipping Physics
2019 #5 Free Response Question - AP Physics 1 - Exam Solution
My solutions to Free Response Question #5 from the 2019 AP Physics 1 Exam. This question is about standing waves in open and closed pipe instruments. Also included are my reflections on how to get perform better on the exam.
Professor Dave Explains
Heterocycles Part 1: Furan, Thiophene, and Pyrrole
We've mentioned heterocycles before. They are cyclic molecules where one or more atoms in the ring are not carbon. Typically these involve oxygen, nitrogen, and sulfur. But there are so many different heterocycles. Different sizes, some...
Professor Dave Explains
Addition on Conjugated Polyunsaturated Systems
Looking at how addition reactions occur on conjugated polyunsaturated systems.
Professor Dave Explains
Heterocycles Part 2: Pyridine
In the previous tutorial, we learned about some five-membered aromatic heterocycles. Those were furan, thiophene, and pyrrole. Now let's learn about a six-membered one, pyridine. This one is ubiquitous in nature, so let's get the scoop...
Virtually Passed
Steady State and Transient Mechanical Vibrations summary
This is a summary of all the videos we've made so far. Notice that our total response = our steady state (particular solution) + our transient (homogeneous solution). In most Engineering applications we will only focus on the steady...
Catalyst University
Postulates of Quantum Mechanics: Orthonormality & Basis Sets
Postulates of Quantum Mechanics: Orthonormality & Basis Sets
Virtually Passed
Harmonic Force Excitation Steady State Amplitude and Phase Proof
Proof of the steady state amplitude and phase for a spring mass damper system with an harmonic load acting on it. Once you get good at it, you don't need to recreate another z equation like I've done. You can just solve as if sin(wt) =...
History Hit
Africa And War: Remembering African Soldiers
The first art piece is a musical that remembers the African soldiers aboard the SS Mendi. The second piece is an art installation that focuses on the very complicated role African soldiers played in the war. Africa And War, Part 1
Physics Girl
Experiments with $100,000+ Speakers
Join Physics Girl and PBS Digital Studios' new show SoundField as they experiment with giant $100,000 speakers and aim them at your body parts looking for resonance, at oobleck, at googly eyes, and at candles to explore the physics of...
Curated Video
Structure and Acoustics of the Trumpet
A trumpet is a musical instrument that amplifies the buzzing sound created by a musician blowing air through their lips. By manipulating the tightness or looseness of their lips, the musician can modify the pitch of the sound. The...
Professor Dave Explains
IIT/JEE Chemistry Practice #27: Resonance Energy
Practice REAL problems from actual past IIT/JEE exams with Professor Dave!