Khan Academy
Hubble's Law, Scale of the Universe, Cosmology and Astronomy
Sal defines and explains the premise of Hubble's Law and then uses trigonometry to show the relationship between velocity and distance. He explains that as the universe expands, objects get farther away from each other; as objects move...
Khan Academy
R,S (Cahn-Ingold-Prelog) Naming System Example 2, Organic chemistry
Repetition of the naming rules and numbering of carbons after diagramming a molecule will help your aspiring chemists. The video builds upon previous examples of naming enantiomers and stereoisomers.
Khan Academy
Naming Alkanes with Alkyl Groups, Organic Chemistry
Sal continues to work through examples of naming carbon chains. He is very clear and logical, so your class should understand this clearly. The video introduces branching and identifying where the additional group is located. Note: A...
Khan Academy
Big Bang Introduction, Scale of the Universe, Cosmology and Astronomy
Sal explains the Big Bang and the spatial concepts of infinity versus a 'sphere' of expanding matter in detail.
Khan Academy
Cahn-Ingold-Prelog System for Naming Enantiomers, Organic Chemistry
1-bromo-1-fluoroethane is the first example of stereoisomers that exhibit different chemical properties and polarize light in distinct ways. An informative video focuses on how to differentiate between enantiomers using the...
Khan Academy
Four Fundamental Forces, Scale of the Universe, Cosmology and Astronomy
Fundamental interactions are the non-contact ways that elementary particles interact. Sal describes electromagnetism, strong interaction, and weak interaction as being mediated by the exchange of gauge bosons between particles.
Khan Academy
Earth Formation, Life on Earth and in the Universe, Cosmology and Astronomy
How was our solar system and Earth formed? Sal hypothesizes that a Supernova was most likely the catalyst that spawned our sun and, consequently, our solar system. He thoroughly explains the formation of the moon and the Earth using a...
Khan Academy
Organic Chemistry Naming Examples 4, Organic Chemistry
Sal continues to work through examples of more complicated carbon chains. He presents a complicated name and attempts to work through it logically, drawing the structure. His humor makes these strategies fun and easy to watch.
Khan Academy
Sn2 Stereochemistry
A short video introduces class members to Sn1 and Sn2 reactions. The study of the stereochemistry of the end product ensures that young chemists can learn not only about the reaction, but can also review the handedness,...
Khan Academy
Supermassive Black Holes, Stars, Black Holes and Galaxies, Cosmology and Astronomy
Following his video on black holes, a video on supermassive black holes explains what happens when a supermassive stellar object collapses. The video primarily explores the reasons we don't see intermediate black holes, as they can be...
Khan Academy
Why Gravity Gets So Strong Near Dense Objects, Cosmology and Astronomy
Sal uses Newtonian physics to explain the relationship between gravity and dense objects. He uses diagrams and relatively straightforward mathematics to demonstrate this concept.
Khan Academy
Cyclic Ethers and Epoxide Naming, Organic Chemistry
An informative video focuses on the categories of ethers, specifically defining the cyclic subset of ethers. Sal examines epoxides and explains why they are significantly more reactive than the generally stable ethers.
Khan Academy
Aldehyde Introduction, Aldehydes and Ketones, Organic Chemistry
Sal clarifies a description that he missed in prior videos about the strong smell of amines. He then recaps and compares many of the small and large aldehydes, taking the opportunity to describe their structure and the progression of...
Khan Academy
Parsec Definition, Stars, Black Holes and Galaxies, Cosmology and Astronomy
What is a parsec? Sal's video explains that a parsec is 3.26 light years and that the word itself can be broken down into "par" (meaning parallax) and "sec" (meaning one arc second). He uses illustrations, diagrams, and trigonometric...
Khan Academy
Parallax in Observing Stars, Cosmology and Astronomy
Parallax is the apparent change of an object determined by the line of sight. Sal defines the concept of parallax and applies it to how we determine the relative distance between us and nearby stars. He draws a diagram to illustrate what...
Khan Academy
A Universe Smaller than the Observable
The universe is much larger than we can imagine, and in many ways, much smaller than we can see. Sal explains how the universe itself may be smaller than the observable universe based on the theory of Cosmic Inflation. The video covers...
Khan Academy
Why Cepheids Pulsate, Stars, Black Holes and Galaxies, Cosmology and Astronomy
Classical Cepheids are supermassive stars that are used to determine distances to galaxies within a local group. Sal explains why Cepheid variables occur, how they are used to determine distances, and the chemistry that creates the...
Khan Academy
Lifecycle of Massive Stars, Stars, Black Holes and Galaxies, Cosmology & Astronomy
A massive star has a mass greater than nine times that of our sun. Sal focuses on the fusion and chemical reactions that take place during the lifecycle of a massive star. He clearly explains the gravitational pull to the chemical...
Khan Academy
Cosmological Time Scale 2, Scale of the Universe, Cosmology and Astronomy
Sal compares the distance of significant objects and the timeline of events in the universe on a scaled timeline across the screen.
Khan Academy
First Living Things on Land Clarification, Cosmology and Astronomy
Sal clarifies concepts covered in the Khan Academy video on Biodiversity in the Phanerozoic Eon. He explains the types of animals and plants that were the first life forms on land. Additionally, he describes what these organisms would...
Khan Academy
Why S-Waves Only Travel in Solids, Cosmology and Astronomy
Starting with a clear diagram to demonstrate how a wave actually forms, an informative video will provide a great summary of s-wave travel. It explains the difference between polar bonds in liquids and the stronger ionic and covalent bonds.
Khan Academy
Hubble Image of Galaxies, Scale of the Universe, Cosmology and Astronomy
Sal gives an example of where the Hubble telescope looks, as well as the level of detail that the camera can see.
Khan Academy
Galactic Collisions, Stars, Black Holes and Galaxies, Cosmology and Astronomy
An interesting video addresses the concept of galactic collisions. He narrates the animated video explaining what is happening and how collisions merge into a new galaxy. Note: While the computations are concrete, the video is theoretical.
Khan Academy
Radius of Observable Universe, Scale of the Universe, Cosmology and Astronomy
The concept of the universe can be incredibly complex on both physical and mathematical levels. Yet Salman Khan can explain concepts that lead to conclusions about the universe's size. He uses intriguing diagrams and presents information...