|Discovered By||Henry Cavendish|
|Density||(0°C, 101.325 kPa) 0.08988 g/L|
|Melting Point||14.01 K, -259.14 °C, -434.45 °F|
|Boiling Point||20.28 K, -252.87°C, -423.17°F|
Hydrogen glows purple when it is in plasma state.
Hydrogen in natureEdit
In its pure form on Earth, hydrogen is usually a gas. Hydrogen is also one of the parts that make up a water molecule. Hydrogen is important because it is the fuel that powers the Sun and other stars. Hydrogen makes up about 75% of the entire universe. Hydrogen's symbol on the Periodic Table of Elements is H.
Pure hydrogen is normally made of two hydrogen atoms connected together. Scientists call these diatomic molecules. Hydrogen will have a chemical reaction when mixed with most other elements. It has no color or smell.
Pure hydrogen is very uncommon in the Earth's atmosphere. In nature, it is usually in water. Hydrogen is also in all living things, as a part of the organic compounds that living things are made of. In addition, hydrogen atoms can combine with carbon atoms to form hydrocarbons. Petroleum and other fossil fuels are made of these hydrocarbons and are commonly used to create energy for human use.
Hydrogen has two different isotopes, called deuterium and tritium. Like regular hydrogen, they both have only one proton and one electron, but deuterium also has one neutron and tritium has two. These other types of hydrogen are important in nuclear energy and organic chemistry reactions.
Some other facts about hydrogen:
- It is a gas at room temperature.
- It acts like a metal when it is solid.
- It is the lightest element in the Universe.
- It is the most common gas element in the Universe.
- It explodes when it touches a flame.
History of HydrogenEdit
The name "hydrogen" comes from the Greek word for water.
Hydrogen was first discovered as a new element in 1776 by Henry Cavendish but other experiments have been done before him, including the 1671 experiment by Robert Boyle.
Uses of HydrogenEdit
Hydrogen as fuel (fusion)Edit
Nuclear fusion is a very powerful source of energy. It relies on forcing atoms together to make helium and energy, exactly as happens in a star like the Sun, or in a hydrogen bomb. This needs a large amount of energy to get started, and is not easy to do yet. A big advantage over nuclear fission, which is used in nuclear power stations, is that no waste is produced, and no toxic fuel like uranium is needed.
There is more than 600 million tons of hydrogen undergoing fusion every second on the Sun.
- Water can be easily broken down into hydrogen and oxygen with electricity, but it takes a lot of electricity to get a usable amount of hydrogen.
- Burning hydrogen combines with oxygen molecules to make steam (pure water).
- A fuel cell combines hydrogen with an oxygen molecule releasing an electron as electricity.
Hydrogen power gridEdit
For these reasons, many peopl believe hydrogen power will eventually replace technologies such as diesel-electric engines and biodiesel fuel.
But it is not correct to see hydrogen as a fuel if it is used in a fuel cell. It is more of a replacement for the power grid. Such a grid and infrastructure with new vehicles might be first made in Iceland, a country that has much free geothermal energy and is quite small. Because it imports all fossil fuel, it would help Iceland to completely stop using it. The huge advantage of hydrogen is that when burnt in an engine or in a fuel cell, there is no pollution. Only a small amount of waer forms.