Practica the aula 3 - Describing your discipline

The chemistry, similarly to physics is the branch of science dealing with problems of matter and energy. It is said that the chemistry is only part of physics...
Chemistry is concentrated on explaining properties of the matter and its interactions with other matter due to withdrawing or gaining electrons from the valence shield of atoms. It is really fascinating science describing how the universe works.

My favorite elements are hydrogen and sodium.

Hydrogen is colorless and odorless gas with the smallest atomic and mass number. It was discovered by Cavendish in eighteenth century. It has only one electron and one proton and its the lightest element in the universe. It has 3 isotopes: proton, deuterium and tritium. It is the most abundant element in universe. Nowadays some researches are carried out about hydrogen as an alternative for fossil fuels energy.

Sodium is white metal. It is very soft, so soft that it can be cut using knife. It is very reactive due to its electron configuration - it has only one electron in the valence shell. It reacts very violently with water - careless carrying out this reaction can be finished by explosion very easy.
Sodium is very important for industrial chemistry. It is component of some of the most important substances in industry. Very well known are sodium bicarbonate, sodium hydroxide, salt and lots of others.