LONDON SCHOOLS
Sponsored by
Information sheet
Hydrogen
What is Hydrogen?
Hydrogen is a chemical element represented by the chemical formula H. Hydrogen atoms consist of one negatively-charged electron that orbits around the nucleus, which in a hydrogen atom consists of a single positively-charged proton.
chemical bonds to one oxygen atom. Water is represented by the chemical formula H2O.
Production of hydrogen
As hydrogen is not commonly found in its pure form on Earth it must be obtained from compounds that contain hydrogen atoms.
Key facts
Pure or ‘elemental’ hydrogen is relatively rare on Earth. Hydrogen is found in small quantities as a gas in the air and is given the formula H2, which means two hydrogen atoms are joined together. On Earth, hydrogen is found mainly in combination with other chemical elements, most commonly with oxygen. Together hydrogen and oxygen form water. In water molecules, two hydrogen atoms are joined by • Hydrogen is found in all living things. • Our bodies are 10% hydrogen, most of which is in the form of water. Hydrogen can be produced on an industrial level from natural gas, which is made from atoms of hydrogen and carbon. However, as natural gas is a non-renewable fossil fuel, this process is not sustainable. A more sustainable way to produce hydrogen is from plant or animal matter, known as biomass, or from water via the process of electrolysis. Electrolysis is the process by which water is split into hydrogen and oxygen using electricity. The electricity used in electrolysis can come from solar power, wind power or other sources of renewable energy.
Key facts
• Hydrogen is the most abundant chemical element in the universe, accounting for 75% of the total amount of chemical elements in the universe. • Most of the hydrogen in the universe is found in clouds of gas in space and in stars.
LONDON HYDROGEN PARTNERSHIP
Partnered with BMW (UK) Ltd
Supported by
LONDON SCHOOLS
Sponsored by
The discovery of hydrogen
Information sheet Hydrogen gas was first discovered in the 1500s, and in 1766 hydrogen was identified in its pure form by the British scientist Henry Cavendish.
Key fact
• The name hydrogen comes from two Greek words: ‘hydro’ meaning water, and ‘gennan’ meaning ‘to make’. Hydrogen therefore means ‘makes water’. It was not until 1783 that hydrogen got its name, when the French chemist Antoine Lavoisier discovered that water is produced when hydrogen is burnt.
Hydrogen fuel cells Electricity can be created from hydrogen using a device known as a hydrogen fuel cell. Fuel cells generate electricity by a process that uses hydrogen and oxygen. Hydrogen atoms are split into electrons and protons. The electrons are forced to travel through a circuit, which creates an electrical current.
Hydrogen in the future
Hydrogen power has many advantages: • When hydrogen is used to generate energy the only by-products are water and heat • Hydrogen is a renewable resource so it will never run out • t is very efficient - hydrogen can produce I three times more energy than the same mass of oil. For these reasons, hydrogen is considered by many people to be the most efficient and environmentally-friendly energy source for the future. Much research is being conducted by businesses, governments and universities to investigate how hydrogen can be used to power cars and electrical appliances. One day our cars, mobile phones, computers, even our homes and schools, could be powered by hydrogen, which could allow us to create a ‘zero emission’ world without pollution from fossil fuels.
Hydrogen power
Hydrogen has the ability to act as an ‘energy carrier’. This means it can be used to store and deliver energy to where it is needed. Hydrogen is often referred to as ‘clean energy’ because when it is used it only produces water and heat. Hydrogen can provide power in two ways: Hydrogen combustion Combustion means ‘burning’. When hydrogen is burnt in the presence of oxygen, heat and water are produced. Combustion engines for cars have been designed that burn hydrogen to produce power instead of burning non-renewable fuel, such as petrol or diesel.
LONDON HYDROGEN PARTNERSHIP
Partnered with BMW (UK) Ltd
Supported by