Khan Academy: Loop De Loop Answer Part 1

The National Chemistry Olympiad exams are comprehensive tests covering an entire  year of chemistry concepts. You can use them as practice for competing in the challenge, or simply as a review, or as an actual final exam for your...

Physics Girl and Simone Giertz team up to challenge each other to answer science riddles as part of an extensive video series on physics. In a subset of three videos, both physics and electronics questions challenge viewers to apply past...

Understand the fatal heart condition Torsades de pointed. [9:59]

An example problem shows how to find the rate constant k from the half-life of a first-order reaction. [6:10]

Find out how a cell that is permeable to one ion can become charged (either positive or negative) if there is permeability and a concentration gradient. Rishi is a pediatric infectious disease physician and works at Khan Academy. [8:21]

Even clothing styles are part of a feedback loop. Learners explore four different examples of feedback loops both outside of and within the body: speed limit signs, thermostats, thermoregulation, and blood glucose levels. They...

A video lecture discussing radioactive decay and half lives. Understand how half life and the mass of the compound remaining is calculated by following the examples given in the lecture. [12:31]

A system presented to figure out how many civilations with enough radioactivity to be detected within the Milky Way. [13:03]

In this video, determine the most and least stable conformations by using the Newman projections. [13:36]

This video explains how to identify torsades de pointes which is a distinctive form of polymorphic ventricular tachycardia. [10:00]