Determining if a reaction is spontaneous by calculating the change in Gibbs free energy. Also calculates the change in entropy using table of standard entropies. Created by Sal Khan. Watch the next lesson: https://www.khanacademy.org/science/chemistry/thermodynamics-chemistry/gibbs-free-energy/v/more-rigorous-gibbs-free-energy-spontaneity-relationship?utm_source=YT&utm_medium=Desc&utm_campaign=chemistry Missed the previous lesson? https://www.khanacademy.org/science/chemistry/thermodynamics-chemistry/gibbs-free-energy/v/gibbs-free-energy-and-spontaneity?utm_source=YT&utm_medium=Desc&utm_campaign=chemistry Chemistry on Khan Academy: Did you know that everything is made out of chemicals? Chemistry is the study of matter: its composition, properties, and reactivity. This material roughly covers a first-year high school or college course, and a good understanding of algebra is helpful. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=sG1ZAdYi13A Note: All Khan Academy content is available for free at (www.khanacademy.org)

Think of a mixed numbers as a number AND a fraction. You can subtract numbers....you can subtract fractions with like denominators. Therefore, you can subtract mixed numbers! Watch. Practice this lesson yourself on KhanAcademy.org right now: https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/mixed-number-add-sub-pre-alg/e/adding_subtracting_mixed_numbers_0.5?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Watch the next lesson: https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/mixed-number-add-sub-pre-alg/v/adding-subtracting-mixed-numbers-1-ex-1?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Missed the previous lesson? https://www.khanacademy.org/math/pre-algebra/fractions-pre-alg/mixed-number-add-sub-pre-alg/v/adding-subtracting-mixed-numbers-0-5-ex-1?utm_source=YT&utm_medium=Desc&utm_campaign=PreAlgebra Pre-Algebra on Khan Academy: No way, this isn't your run of the mill arithmetic. This is Pre-algebra. You're about to play with the professionals. Think of pre-algebra as a runway. You're the airplane and algebra is your sunny vacation destination. Without the runway you're not going anywhere. Seriously, the foundation for all higher mathematics is laid with many of the concepts that we will introduce to you here: negative numbers, absolute value, factors, multiples, decimals, and fractions to name a few. So buckle up and move your seat into the upright position. We're about to take off! ... https://www.youtube.com/watch?v=q19UnHEofOA Note: All Khan Academy content is available for free at (www.khanacademy.org)

Kim discusses how John Rolfe's discovery that Virginia was the perfect environment to cultivate tobacco led to Jamestown's success -- and to a great deal of conflict between the English and the Powhatans, resulting in the first and second Anglo-Powhatan Wars. ... https://www.youtube.com/watch?v=jZnJLEyJtBU Note: All Khan Academy content is available for free at (www.khanacademy.org)

We're going to put our order of operations knowledge to work as we evaluate this expression. Exponents, specifically, are our focus here. Watch the next lesson: https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-expressions-and-variables/cc-6th-parts-of-expressions/v/expression-terms-factors-and-coefficients?utm_source=YT&utm_medium=Desc&utm_campaign=6thgrade Missed the previous lesson? https://www.khanacademy.org/math/cc-sixth-grade-math/cc-6th-expressions-and-variables/cc-7th-evaluating-expressions-word-problems/v/evaluating-expressions-3-exercise?utm_source=YT&utm_medium=Desc&utm_campaign=6thgrade Grade 6th on Khan Academy: By the 6th grade, you're becoming a sophisticated mathemagician. You'll be able to add, subtract, multiply, and divide any non-negative numbers (including decimals and fractions) that any grumpy ogre throws at you. Mind-blowing ideas like exponents (you saw these briefly in the 5th grade), ratios, percents, negative numbers, and variable expressions will start being in your comfort zone. Most importantly, the algebraic side of mathematics is a whole new kind of fun! And if that is not enough, we are going to continue with our understanding of ideas like the coordinate plane (from 5th grade) and area while beginning to derive meaning from data! (Content was selected for this grade level based on a typical curriculum in the United States.) About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. ... https://www.youtube.com/watch?v=0uCslW40VHQ Note: All Khan Academy content is available for free at (www.khanacademy.org)