Question

what is the between atoms and molecules? how do compounds and elements differ?

Answer 1

An atom is smallest particle in an element that has the properties of the element. It is not possible to breakdown the atom further retaining the properties of the element. Atoms are not visible to the naked eye and are the basic building blocks. For example the atoms of element gold cannot be broken down further and each atom has the properties of gold.

Molecules are formed by the combination of two or more atoms. Unlike atoms, molecules can be subdivided to individual atoms. The atoms are bonded together in a molecule. Molecules also are not visible to the naked eye, while can be seen through highly magnifying microscopes and other scientific devices. Water is comprised of numerous water molecules. Each water molecule is made up of one oxygen atom and two hydrogen atoms. So a water molecule can be further divided into oxygen and hydrogen atoms. But these atoms cannot be subdivided. In a molecule, atoms are bonded together by single, double, or triple bonds.

An atom has a nucleus surrounded by electrons. The electrons are negatively charged particles. The nucleus contains neutrons and positively charged protons. Depending on the majority of the particles, the atom can be positively or negatively charged. When these charged atoms bond together to form molecules, the bonds are formed by the electrons filling up the outer orbits of the atoms. Since atoms exist independently, there is no bonding in an atom.

When atoms combine in different numbers to form a molecule, the end result can vary. For example, when two atoms of oxygen combine to form a molecule, it becomes O₂ which is the oxygen we breathe in. But when three oxygen atoms combine to form an O₃ molecule, it becomes Ozone. So another difference between atoms and molecules is that when similar atoms combine together in varying numbers, molecules of different properties can be formed. But when similar molecules combine together in any numbers, a simple product is formed.

A molecule is usually stable to exist by itself but an atom is not stable by itself. This is owing to the presence of electrons in the atoms. Only when sufficient number of electrons are present in an atom, it becomes stable. The sufficient number of electrons are received in an atom, when two atoms bond together and share the electrons. Thus it becomes stable and forms a molecule. Not all atoms can bond together. The bonding depends on the charge and chemical properties of the atoms.

compounds and elements

Elements and compounds are pure chemical substances found in nature. The difference between an element and a compound is that an element is a substance made of same type of atoms, whereas a compound is made of different elements in definite proportions. Examples of elements include iron, copper, hydrogen and oxygen. Examples of compounds include water (H₂O) and salt (Sodium Chloride - NaCl)