The greenhouse effect is a natural process that warms the Earth's surface. When the Sun’s energy reaches the Earth, some of it is reflected back to space, and the rest is absorbed by the land, oceans, and atmosphere....

Physics, Science, Middle school Keywords: Density, uphtrust (buoyancy), liquids, gases, pressure, floating, lifting, sinking, overall density, average density Presents the concept of upthrust, and how the relation...