Atoms and molecules

The atom it is the basic unit of matter. The molecule is the result of the union of two or more atoms, that is, molecules are made up of atoms.

What is an atom?

Atoms are the fundamental building blocks of the Universe. The definition of the atom is the least amount of matter that retains the chemical properties of the element.

For example, if we take a piece of silver Ag, which is an element, and divide it so many times to the point that it can no longer be divided without losing the properties that characterize it as silver, we will be in the presence of a silver atom.

The atom is composed of:

• a central core: made up of neutrons and protons.
• an electronic cloud: where are the electrons surrounding the nucleus.

The number of protons, neutrons and electrons determines the basic structure of an atom.

Examples of atoms

There are as many atoms as there are elements in the periodic table. Let's see some examples of atoms and their characteristics.

Hydrogen H

Hydrogen is the simplest atom in the Universe, made up of a proton and an electron. Its atomic number is 1, making it the first element in the periodic table..

Oxygen O

Oxygen is one of the most important elements for living beings. Its atomic number is 8 and it is made up of 8 neutrons, 8 protons and 8 electrons..

Carbon C

Carbon C is the atom present in all organic compounds; it has six neutrons and six protons in the nucleus and six electrons in the electron cloud. Of the six electrons, four are found in the outermost shell, these are the electrons available to form bonds with other atoms and form molecules.

You may be interested in seeing elements, compounds and mixtures.

What is a molecule?

A molecule is the result of the union of two or more atoms. Electrons found in the outermost shell of an atom (valence electrons) when shared between atoms, form a molecule.

The molecule is the smallest part of a substance. Molecules made up of two atoms are called diatomic, for example, the O_two molecular oxygen, nitrogen from air N_two and chlorine gas Cl_two.

There are molecules made up of hundreds of atoms. For example, the chlorophyll molecule is made up of 55 carbon atoms, 72 hydrogen atoms, one magnesium atom, 4 nitrogen atoms, and 5 oxygen atoms, with a total of 137 atoms..

Examples of molecules

In the Universe there are an infinity of molecules, of which we only mention a few.

H_two diatomic hydrogen

The simplest molecule is diatomic hydrogen H_two, formed by two hydrogen atoms joined by a covalent bond, where electrons are shared between the two atoms.

Water

Water H_twoO is a triatomic molecule, as it is made up of three atoms. Its particular structural conformation gives it a dipolar character, with a negative partial charge at the oxygen end and two positive partial charges at the hydrogens..

Glucose

Glucose is a type of sugar. The sugar molecule contains six carbon atoms, twelve hydrogen atoms, and six oxygen atoms..

You may be interested in seeing:

• Types of chemical bonds.
• States of matter and properties of matter.