Why do we have capital letters? Because the majority of the letters in the alphabet we use came from Latin. This question is actually the wrong way round. It should be asking why we have lowercase letters. The majority of our writing these days is done in lowercase with the occasional capital letter thrown in, […]
#709 Why do we have capital letters? Read More »
What is the pH scale? It probably stands for potential of hydrogen and it shows how much hydrogen is in a substance. The pH scale is written with a capital H because the symbols for the elements are always written with a capital. However, when the scale was invented by a Danish chemist called Soren
#708 What is the pH scale? Read More »
Why are bridges designed to move? Because they expand and contract, because the wind moves them, and because the land on either side of them moves. When you drive on and off a bridge, you may have noticed there is a slight gap at either end. This gap usually has a metal bracket on it
#707 Why are bridges designed to move? Read More »
Why do we sneeze? We usually sneeze in order to remove an irritant from the nose. There are many different things that make people sneeze, but the most common cause is when there is an irritant in the nose. This could be smoke particles, it could be dust, it could be anything. The nose is
#706 Why do we sneeze? Read More »
Why do many Americans drink coffee and many British people drink tea? Because Americans boycotted tea before, during, and after the War of Independence and because the British government gained more money from taxing tea. The two countries both started as polar opposites and have ended up as polar opposites. Tea was more popular than
#705 Why do many Americans drink coffee and many British people drink tea? Read More »
Why does iron rust? The iron atoms react with oxygen molecules to produce iron oxide, which is rust. Other metals don’t rust because only iron, or metals with an iron alloy can rust. This is because rust is iron oxide. Other metals can react with oxygen in different ways or corrode, but only iron can
#704 Why does iron rust? Read More »
Is a starfish a fish? No, starfish are not fish. Fish are vertebrate animals that live in the sea, have gills to breathe through, have a two chambered heart, are cold blooded, and have a brain and central nervous system. Starfish live in the sea, but that is where the similarity stops. These days, many
#703 Is a starfish a fish? Read More »
Why is mercury poisonous? It can damage the nervous system, kidneys, liver, and immune systems of people and animals. Mercury is a heavy metal. Heavy metals are metals that are very dense and have a high atomic number. Mercury has an atomic number of 80. It melts at -38.83℃, which means it is liquid at
#702 Why is mercury poisonous? Read More »
Do all liquids expand when they freeze? No. Water is the only liquid that expands when it freezes. There are four states of matter: solid, liquid, gas, and plasma. As almost all substances go from the solid phase to the liquid phase and then to the gas phase, they become less dense. This is all
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How does a helicopter with two rotors work? The rotors rotate in opposite directions and are on a transmission so that they don’t collide with each other There are over twenty different types of helicopter that have two rotors. The Chinook is probably the most famous. It was invented in 1961, but the first tandem-rotor
#700 How does a helicopter with two rotors work? Read More »
