A chemical element is defined as any pure chemical substance, consisting of a single unique atom, distinguished by its atomic number (the number of protons in the nucleus of an atom), and either found naturally in the earth as oxygen or formed by humans such as bromine. 91 of them are found in nature in their natural form, and the elements are classified into metals, non-metals, or semi-metals according to their position in the periodic table. Among the states of the elements are gaseous states such as lithium, liquid state such as mercury, and solid state such as gold and copper.

Periodic Table

The periodic table organizes all the elements into horizontal rows known as periods, and columns known as groups, so that they are arranged in ascending order according to the atomic number. The element is the core of matter, and for thousands of years now, scientists have been in continuous and serious research to discover the chemical elements and know their properties. Scientists have classified the elements in order to facilitate their study, and in order to find a relationship between the elements and their chemical and physical properties. Mendeleev’s periodic table was the first real periodic table to classify The elements, where the elements are arranged according to their weight in ascending order from left to right of the table.

General properties of the elements

The elements are classified into groups, and the elements of one group are similar in their properties; Because the number of valence electrons in the last orbital is the same:

  • Metals: Good conductors of heat and electricity, they have luster and luster, their density is high, and therefore their melting point is high, and they tend to lose electrons.
  • Metalloids: They have the properties of metals and non-metals, are solid, shiny and matte, can be drawn and forged, and are less conductive of heat and electricity than metals.

chemical compound

A chemical compound is defined as a chemical substance composed of two or more elements, such as sodium chloride and water. Compounds have many cases, most of the compounds are found in the solid state at low temperatures, and they can also exist in the liquid, gas or plasma state, and the properties of the compounds differ from the properties of the elements involved in the composition, and according to the law of fixed proportions, the compound always consists of the same The elements have fixed mass ratios. The uses of chemical compounds are:

  • The acid compound reacts with the base compound to produce water and salt.
  • Some alkaline compounds are used in household cleaners.
  • Basic and acidic solutions are used to conduct electric current.
  • Some acidic compounds are used in the manufacture of soft drinks, plastics and rubber, and in the manufacture of fertilizers and animal feed.
  • Some basic compounds are used in the pharmaceutical industry, such as antacid drugs.

Elements and compounds

Writing – on the date : – Last updated: 2022-05-11 14:36:02