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 […]
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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
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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
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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
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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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Why does a boomerang come back? One wing travels faster than the other which causes it to fly in a circular path. However, not all boomerangs are designed to come back and the one most people are probably thinking of is the modern version of the boomerang. The boomerang was a weapon used by the
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What are rare earth metals? They are a group of 17 elements on the periodic table that are spread out so much in the earth that they are difficult to mine, hence the name “rare”. There are seventeen rare earth elements, and they all have different uses. Here they are with their uses: Yttrium –
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Why are electromagnets stronger than permanent magnets? Because the amount of current and the number of coils in the copper wire can increase the strength of an electromagnet while a permanent magnet cannot be any more magnetic than it already is. The strength of a magnet is measured in different ways, but one way is
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How does ceramic armor work? It shatters the projectile, absorbing and spreading out the kinetic energy from the projectile over a wider area. The first thing to clear up is that ceramic armor plates are made of a different type of ceramics than the mugs and cups in your kitchen. There are many different types
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Why do tattoos stay in the skin forever? Because the particles of ink are too big for the body to absorb and expel. When you have a tattoo, the tattooist uses a needle to put ink particles into your skin. Skin has three layers, and the ink is injected into the middle layer, the dermis.
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