30 results for “air”
Planet Earth
The Atmosphere
air is Dry air is about 78 percent nitrogen, 21 percent oxygen and just under one percent
Article · 4 min read
The Human Body
Lungs and Breathing
air is drawn in. Relax, and the chest springs back and the air flows out. At rest
Article · 4 min read
Planet Earth
Weather and Climate
air is lighter than cold air, so at the equator heated air rises, spreads toward the poles
Article · 4 min read
Matter, Energy & Physics
Sound
air is spread out. These bands of squashed and stretched air, called compressions and rarefactions, spread
Article · 3 min read
Plants & Fungi
Trees and Forests
air and keep it there for centuries. In doing so they have become the largest, heaviest
Article · 4 min read
Plants & Fungi
Photosynthesis: How Plants Eat Light
air into sugar and oxygen. It is the chemical reaction that feeds almost everything alive. Plants
Article · 3 min read
Matter, Energy & Physics
Energy and Heat
air around you are flying about at hundreds of metres a second, colliding billions of times
Article · 4 min read
Matter, Energy & Physics
Electricity and Magnetism
air can no longer hold it apart, and hundreds of millions of volts discharge in a channel
Article · 4 min read
The Human Body
The Senses
air, pressure on the skin: none of these are experiences in themselves. They are physical events
Article · 4 min read
Planets & the Solar System
Mars
air is almost all carbon dioxide and so thin that the pressure at the surface is less
Article · 4 min read
Planet Earth
Volcanoes
air breathable and can bury cities in hours. In August of the year 79, the people
Article · 4 min read
Animals
Birds
air sacs that keeps fresh air flowing through the lungs on both the in-breath and the out-breath
Article · 3 min read
Animals
Insects
Air enters through small holes along the sides of the body and travels through tubes directly
Article · 3 min read
The Human Body
Skin, Hair and Nails
Your skin is your largest organ: a waterproof, self-repairing shield that senses touch, controls your
Article · 3 min read
Chemistry
Acids and Bases
air, which forms carbonic acid and slowly lowers their pH. More acidic water makes it harder
Article · 3 min read
Planets & the Solar System
Mercury and Venus
air. The clouds are made of sulphuric acid, and they reflect so much sunlight that Venus
Article · 3 min read
Animals
Whales and Dolphins
air, through blowholes on the top of the head, and must surface to do so; a whale
Article · 4 min read
Life & Biology
Bacteria and Viruses
air, which plants cannot use, and convert it into forms plants can absorb; every protein molecule
Article · 4 min read
Animals
Reptiles and Amphibians
creatures ever to breathe air on land, still doing it their way, 370 million years on.
Article · 3 min read
Life & Biology
Ecosystems and Food Webs
air, sunlight and climate. It can be as small as a rotting log or as large
Article · 4 min read
Planet Earth
Rocks, Minerals and Fossils
air, when ice ages came and went, where continents stood and how life responded. They hold
Article · 4 min read
Space & the Universe
Exoplanets: Worlds Around Other Stars
air When a planet transits its star, a little starlight passes through the planet's atmosphere
Article · 3 min read
Planet Earth
Inside the Earth
air and sea, keeping the climate habitable over geological time. The core's magnetic field protects
Article · 4 min read
Space & the Universe
Nebulae
air you are breathing contains about 25 billion billion molecules in the same volume. The best
Article · 3 min read
Planets & the Solar System
The Sun
air unevenly. Rivers flow because it lifts water into clouds. Only nuclear and geothermal power owe nothing
Article · 4 min read
Animals
Mammals
air with lungs. These traits define the mammals, a group of about 6,500 species that
Article · 4 min read
Life & Biology
Evolution
air was cleaned. In the Galápagos, Darwin's finches have been watched evolving beak size in response
Article · 4 min read
The Human Body
The Immune System
air you just breathed, there are microbes that would kill you if they could. Almost none
Article · 4 min read
Matter, Energy & Physics
Gravity
air resistance, a heavy ball and a light one dropped together land together. In 1971 an astronaut
Article · 4 min read
Plants & Fungi
Fungi
air you breathe contains thousands in every cubic metre. Some are fired from their mushrooms with
Article · 4 min read
