How do strong and weak acids differ? Use lab tools on your computer to find out! Dip the paper or the probe into solution to measure the pH, or put in the electrodes to measure the conductivity. Then see how concentration and strength affect pH. Can a weak acid solution have the same pH as a strong acid solution?

These courses, produced by the Massachusetts Institute of Technology, introduce the fundamental concepts and approaches of aerospace engineering, highlighted through lectures on aeronautics, astronautics, and design. MIT˘ď‹ď_s Aerospace and Aeronautics curriculum is divided into three parts: Aerospace information engineering, Aerospace systems engineering, and Aerospace vehicles engineering. Visitors to this site will find undergraduate and graduate courses to fit all three of these areas, from Exploring Sea, Space, & Earth: Fundamentals of Engineering Design to Bio-Inspired Structures

Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.

Watch alpha particles escape from a polonium nucleus, causing radioactive alpha decay. See how random decay times relate to the half life.

This class analyzes complex biological processes from the molecular, cellular, extracellular, and organ levels of hierarchy. Emphasis is placed on the basic biochemical and biophysical principles that govern these processes. Examples of processes to be studied include chemotaxis, the fixation of nitrogen into organic biological molecules, growth factor and hormone mediated signaling cascades, and signaling cascades leading to cell death in response to DNA damage. In each case, the availability of a resource, or the presence of a stimulus, results in some biochemical pathways being turned on while others are turned off. The course examines the dynamic aspects of these processes and details how biochemical mechanistic themes impinge on molecular/cellular/tissue/organ-level functions. Chemical and quantitative views of the interplay of multiple pathways as biological networks are emphasized. Student work will culminate in the preparation of a unique grant application in an area of biological networks.

As currently taught in the United States, introductory courses in analytical chemistryemphasize quantitative (and sometimes qualitative) methods of analysis along with a heavydose of equilibrium chemistry. Analytical chemistry, however, is much more than a collection ofanalytical methods and an understanding of equilibrium chemistry; it is an approach to solvingchemical problems. Although equilibrium chemistry and analytical methods are important, theircoverage should not come at the expense of other equally important topics.

The introductory course in analytical chemistry is the ideal place in the undergraduate chemistry curriculum forexploring topics such as experimental design, sampling, calibration strategies, standardization,optimization, statistics, and the validation of experimental results. Analytical methods comeand go, but best practices for designing and validating analytical methods are universal. Becausechemistry is an experimental science it is essential that all chemistry students understand theimportance of making good measurements.

My goal in preparing this textbook is to find a more appropriate balance between theoryand practice, between “classical” and “modern” analytical methods, between analyzing samplesand collecting samples and preparing them for analysis, and between analytical methods anddata analysis. There is more material here than anyone can cover in one semester; it is myhope that the diversity of topics will meet the needs of different instructors, while, perhaps,suggesting some new topics to cover.

This open course with a new set of ancillary materials for OpenStax Chemistry was created under a Round Eleven Mini-Grant for Ancillary Materials Creation and Revision. The materials created in order to support faculty implementing OpenStax Psychology in the classroom include:

Lecture Slides
Chapter Checklists
Practice Problems
Newly-Created Videos
Along with these resources, the open course also contains a laboratory section with new instructional videos, a laboratory notebook and a sample notebook with responses, and experiments for each course.

Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction.

Explore the interactions between various combinations of two atoms. Turn on the force arrows to see either the total force acting on the atoms or the individual attractive and repulsive forces. Try the "Adjustable Attraction" atom to see how changing the parameters affects the interaction.

Chemistry is the study of matter, and all matter is made up of atoms. We will learn about elements, atomic number and mass, isotopes, moles (chemistry moles, not the animal), and compounds.

Play with objects on a teeter totter to learn about balance. Test what you've learned by trying the Balance Challenge game.

How do you know if a chemical equation is balanced? What can you change to balance an equation? Play a game to test your ideas!

Experiment with a helium balloon, a hot air balloon, or a rigid sphere filled with different gases. Discover what makes some balloons float and others sink.

Students explore static electricity by rubbing a simulated balloon on a sweater. As they view the charges in the sweater, balloon, and adjacent wall, they gain an understanding of charge transfer. This item is part of a larger collection of simulations developed by the Physics Education Technology project (PhET). The simulations are animated, interactive, and game-like environments.

Why does a balloon stick to your sweater? Rub a balloon on a sweater, then let go of the balloon and it flies over and sticks to the sweater. View the charges in the sweater, balloons, and the wall.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

Explore the origin of energy bands in crystals of atoms. The structure of these bands determines how materials conduct electricity.

This is a free textbook offered by Saylor Foundation. The Basics of General, Organic, and Biological Chemistry by David W. Ball, John W. Hill, and Rhonda J. Scott is a new textbook offering for the one-semester GOB Chemistry course. The authors designed this book from the ground up to meet the needs of a one-semester course. It is 20 chapters in length and approximately 350-400 pages; just the right breadth and depth for instructors to teach and students to grasp. In addition, The Basics of General, Organic, and Biological Chemistry is written not by one chemist, but THREE chemistry professors with specific, complimentary research and teaching areas. David W. Ball’s specialty is physical chemistry, John W. Hill’s is organic chemistry, and finally, Rhonda J. Scott’s background is in enzyme and peptide chemistry. These three authors have the expertise to identify and present only the most important material for students to learn in the GOB Chemistry course.

Look inside a resistor to see how it works. Increase the battery voltage to make more electrons flow though the resistor. Increase the resistance to block the flow of electrons. Watch the current and resistor temperature change.

Look inside a battery to see how it works. Select the battery voltage and little stick figures move charges from one end of the battery to the other. A voltmeter tells you the resulting battery voltage.