A scale model is a representation or copy of an object that is larger or smaller than the actual size of the object being represented. Very often the scale model is smaller than the original and used ... > more
An underwater explosion, also known as an UNDEX, is an explosion beneath the surface of water. The type of explosion may be chemical or nuclear. They are categorised in accordance with their depth ... > more
The electron microscope is a type of microscope that uses electrons to create an image of the target. It has much higher magnification or resolving power than a normal light microscope.
Although ... > more
A single chemical reaction is said to have undergone autocatalysis, or be autocatalytic, if the reaction product is itself the catalyst for that reaction.
A set of chemical reactions can be said to ... > more
Physics is the science of matter and its motion—the science that deals with concepts such as force, energy, mass, and charge. As an experimental science, its goal is to understand the natural ... > more
Iron is a chemical element with the symbol Fe and atomic number 26. Iron is a group 8 and period 4 metal. Iron is the most abundant metal on Earth, and is believed to be the tenth most abundant ... > more
Polonium is a chemical element in the periodic table that has the symbol Po and atomic number 84. A rare and highly radioactive metalloid, polonium is chemically similar to tellurium and bismuth, and ... > more
RADAR is a system used to detect, range, and map objects such as aircraft, ships, and rain. Powerful radio waves are transmitted, and a receiver listens for any echoes. By analysing the reflected ... > more
A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers). Helicopters are classified as rotary-wing aircraft to distinguish them from conventional ... > more