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Science
Middle school biology - NGSS
Learn biology using videos, articles, and NGSS-aligned practice. Review the fundamentals of cell biology, organism growth and reproduction, photosynthesis, cellular respiration, ecology, genetics, evolution, and natural selection.Middle school Earth and space science - NGSS
Learn Earth and space science using videos, articles, and NGSS-aligned practice. Review the fundamentals of space systems, weather and climate, Earth's history and systems, and human impacts.Middle school physics - NGSS
Learn physics using videos, articles, and NGSS-aligned practice exercises. Review the fundamanetals of motion, forces, energy, and waves.High school biology - NGSS
Learn biology using videos, articles, and NGSS-aligned practice. Review the fundamentals of cell biology, physiology, genetics, biochemistry, natural selection, and ecology.High school physics
This algebra-based course covers the main topics in high school introductory and honors physics, including motion, force, work, energy, momentum, collisions, torque, waves, sound, static electricity, and circuits.High school physics - NGSS
Learn High School Physics using videos, articles, and NGSS-aligned practice. Review the fundamentals of kinematics, forces, fields, energy in systems, electromagnetic radiation, and communication technology.AP®︎/College Biology
Learn AP Biology using videos, articles, and AP-aligned multiple choice question practice. Review the fundamentals of biochemistry, cell biology, genetics, evolution, and ecology, and develop scientific thinking skills as you explore the study of life.AP®︎/College Chemistry
Learn AP Chemistry using videos, articles, and AP-aligned practice. Review the fundamentals of atomic structure, intermolecular forces and bonding, chemical reactions, kinetics, thermodynamics, and equilibrium.AP®︎/College Environmental science
Learn AP Environmental Science using videos, and AP-aligned practice. Review the fundamentals of ecosystems, biodiversity, populations, earth systems and resources, land and water use, energy resources and consumption, pollution, and global change.AP®︎/College Physics 1
Learn AP Physics using videos, articles, and AP-aligned practice. Review the fundamentals of kinematics, dynamics, energy, and momentum.AP®︎/College Physics 2
An algebra-based, introductory college-level physics course that explores topics such as fluid statics and dynamics; thermodynamics with kinetic theory; PV diagrams and probability; electrostatics; electrical circuits with capacitors; magnetic fields; electromagnetism; physical and geometric optics; and a whole lot more.Organic chemistry
Sal and Jay cover topics covered in college organic chemistry course. Basic understanding of basic high school or college chemistry assumed (although there is some review).Cosmology and astronomy
It's a great, big universe out there. In this section of Khan Academy, you'll learn about the brain-bending vastness of time and space. We go from plate tectonics here on Earth to entire galaxies and beyond.Electrical engineering
Learn about electricity, circuit theory, and introductory electronics. We also have sections that let you get down and dirty with household items, from building your own robot to videos where we disassemble household items to see what's inside.Biology library
Welcome to the Biology library! Biology is the study of life. Here, you can browse videos, articles, and exercises by topic. We keep the library up-to-date, so you may find new or improved content here over time.Chemistry library
Chemistry is the study of matter and the changes it undergoes. Here you can browse chemistry videos, articles, and exercises by topic. We keep the library up-to-date, so you may find new or improved material here over time.Physics library
Welcome to the Physics library! Physics the study of matter, motion, energy, and force. Here, you can browse videos, articles, and exercises by topic. We keep the library up-to-date, so you may find new or improved material here over time.A brief introduction to biology
Biology, defined as the scientific study of life, is an incredibly broad and diverse field. In many ways, it's as kaleidoscopic and rich as living organisms themselves. Biologists study life at many scales, from cells to organisms to entire ecosystems. Begin your own biological journey here!
Start learningA brief introduction to biology
Biology, defined as the scientific study of life, is an incredibly broad and diverse field. In many ways, it's as kaleidoscopic and rich as living organisms themselves. Biologists study life at many scales, from cells to organisms to entire ecosystems. Begin your own biological journey here!
Start learningA brief introduction to physics
Physics is the study of the basic principles that govern
the physical world around us. We'll start by looking at
motion itself. Then, we'll learn about forces, momentum,
energy, and other concepts in lots of different physical
situations. To get the most out of physics, you'll need a
solid understanding of algebra and a basic understanding
of trigonometry.
Start learningA brief introduction to physics
Physics is the study of the basic principles that govern
the physical world around us. We'll start by looking at
motion itself. Then, we'll learn about forces, momentum,
energy, and other concepts in lots of different physical
situations. To get the most out of physics, you'll need a
solid understanding of algebra and a basic understanding
of trigonometry.
Start learningA brief introduction to chemistry
We will be covering the material in a first year
introductory high school or college general chemistry
course. This may be your first time taking chemistry, but
chances are you know a lot of chemistry already from
observing the world around you. We will learn how to
explain phenomena by thinking in terms of the atoms that
make up all matter, and how atoms interact. Basically,
learning chemistry is like having telescopic vision!
Start learningA brief introduction to chemistry
We will be covering the material in a first year
introductory high school or college general chemistry
course. This may be your first time taking chemistry, but
chances are you know a lot of chemistry already from
observing the world around you. We will learn how to
explain phenomena by thinking in terms of the atoms that
make up all matter, and how atoms interact. Basically,
learning chemistry is like having telescopic vision!
Start learning