Compounds

Compounds

Compounds are groups of two or more elements that are tied together. They are created when two different atoms share the same electron or when electrons travel from one atom to another.

Every compound has certain features and a chemical formula. Water, for example, is a compound that has two hydrogen atoms and one oxygen atom in it . Its chemical formula is H 2O. When sodium (Na) combines with chlorine (Cl) you get a compound called salt (NaCl). Carbon and hydrogen atoms form methane, or natural gas (CH 4).

Compounds can be divided into two groups: organic compounds always have carbon atoms in them. You can find them in all living creatures, in plants and in a lot of our food, for example sugar and fat. All other compounds are called inorganic compounds.

Compounds can be solids, liquids or gases. They may also turn into many different colours. Some compounds react very quickly, others don’t react at all.

Important Elements 

Hydrogen

The hydrogen atom is the smallest that we know and it has a very simple structure: one proton with a positive charge and one electron with a negative charge.

Hydrogen occurs as a gas that you can’t see and can’t smell. It is about 14 times lighter than air. When you combine two atoms of hydrogen with one atom of oxygen you get a water molecule H 2O. Like nitrogen, hydrogen can also be condensed to a liquid that freezes at – 259°C (-434°F) and boils at -252°C (-423°F)

Hydrogen is one of the most common elements in our universe. The sun and many stars are made of hydrogen. It can also be found in the earth’s crust. Hydrogen is in many compounds of animals and plants.

Hydrocarbons are compounds that only have hydrogen and carbon in them, like petroleum, natural gas or plastic.

Hydrogen has many uses. When two hydrogen atoms get together they form a molecule and give off a lot of heat. That’s why, together with oxygen, hydrogen makes a good fuel. It, for example, powers the engines of space rockets. Power plants use hydrogen to produce energy. There are even cars that run on hydrogen fuel. When you add hydrogen to coal you can make petrol.

Helium

Helium is a light, colourless gas that you can’t smell. It belongs to the group of noble gases because you cannot combine it with other elements. It has two protons and two neutrons.

Like hydrogen, we can find helium everywhere in our universe. On Earth, helium can be found in natural gas and in the atmosphere. It is so light that it rises and escapes into the atmosphere.

Helium is used to fill balloons. They can rise very high because helium is lighter than air. It is also safer than hydrogen because it does not burn.

People who suffer from asthma sometime inhale helium and oxygen because helium can enter the lungs more easily.

Nitrogen

Nitrogen is a colourless gas that you can’t smell. It makes up about 78 % of the Earth’s atmosphere.

Nitrogen’s chemical symbol is N. Its atomic number is 7 and its mass is 14. Nitrogen gas has two atoms bonded together to form a molecule. The gas can be made into a liquid that freezes at -209° and boils at 195 ° C.

All plants and animals must have nitrogen to live. It is part of all amino acids. Plants produce these acids themselves, animals only produce some of them and get the rest by eating other animals and plants,

Nitrogen is also used as a fertilizer, which plants need to grow.

Iron

Iron is a silvery, white metal that you can find in rocks. Its chemical symbol is Fe, for ferrum. It has 26 protons and a mass of 56.

The industry gets pure iron out of ore that is melted at a high temperature about 1,500 ° C.

All plants, animals and human beings need iron. Most iron in our body is in the red blood cells where it helps to form haemoglobin. Haemoglobin carries oxygen to all parts of our body. We also need iron in your muscles. So it’s important to eat enough food with iron in it, or else you might get tired and weak

Carbon

Carbon is one of the most important elements. All living creatures have carbon in them and the industry uses carbon in many ways.

Carbon’s chemical symbol is C. Its atomic number is 6 and it has a mass of 12, but there are other isotopes of carbon too.

Carbon atoms like to form bonds with other atoms. They can link together with other elements and form very long chains.

A lot of carbon on Earth is found together with other elements. Carbon dioxideis in the air that we breathe out. Minerals, like limestone have carbon in them. Mixtures of carbon and hydrogen are in petroleum and natural gas.

Pure carbon does not occur very often on Earth. The best known forms of pure carbon are diamonds and graphite.

Diamonds are the hardest objects on Earth. They are in the Earth’s crust, formed under high temperatures and pressure. Diamonds are very valuable. Most of them are used in industry—to cut or polish other objects or as drilling heads in oil fields.