Compound Molecules – When you were in school, Sinaumed’s must have received explanations
about atomic and molecular matter , especially in chemistry subjects? Yep,
atoms, molecules, ions, and these compounds are some of the main topics in chemistry learning which are
the smallest particles of an object and cannot be seen with the naked eye. That is why in
chemistry lessons often use a tool in the form of a microscope.
However, if there is a question about what a compound molecule is and the relationship between the two, can
Sinaumed’s answer it? Some people often think that the two types of particles are the
same, but actually they are not … Then, what is a compound molecule?
How is the relationship between the two? How is the application of the existence
of compound molecules in everyday life? So, so that Sinaumed’s understands
this, let’s look at the following review!
Understanding Compound Molecules
If you look at KBBI (Big Indonesian Dictionary), the term “molecule” is always related to the field of Physics
which has a definition in the form of ‘the smallest part of a compound formed from a group of atoms that are
chemically bonded’ and ‘the smallest part of a compound that is still capable of exhibiting the
properties of -the nature of the compound’ . Meanwhile, the term “compound” can be
defined as ‘a pure and homogeneous substance consisting of two or more different elements in a certain
ratio, usually whose properties are very different from those of the elements’.
So, based on this definition, it can be concluded that the molecule of this compound is the smallest
particle of a compound that still has the same properties as that compound. This compound
molecule can be formed through the process of combining atoms of the same elements (elemental molecules) or
atoms of different elements (compound molecules).
Basically, every compound is a molecule, but not all molecules are compounds. So,
it can be said that this compound is a subset of the existence of a molecule.
An example of the presence of a compound molecule is carbon monoxide in the form of CO (CO), water (HHO), and
carbon dioxide (OCO).
Relationship of Molecules With Compounds
If traced once again, the compound is a combination or amalgamation of the presence of two or more
different elements but bound in a certain fixed proportion or ratio. Well, in a compound must
have a similar arrangement of molecules. For example, in the compound calcium carbonate, which
is composed of the presence of molecules of the elements Ca, C, and O in a fixed arrangement.
From this arrangement, a CaCO3 molecule is formed, namely in the form of 40% mass Ca, 48% mass O,
and 12% mass C, the ratio of which is always fixed in the CaCO3 compound.
Basically, every compound is a molecule, but not all molecules are compounds. So, it can be
said that this compound is a subset of the existence of a molecule.
Examples of Compound Molecules and Their
Benefits in Life
| Compound Molecules | Chemical Formulas | Benefits In Life |
| Acetic acid | CH3COOH | As food vinegar |
| Ammonia | NH3 | As a plant fertilizer |
| Ascorbic acid | C6H8O6 | As vitamin C for the body |
| Calcium carbonate | CaCO3 | Building material |
| Baking soda | NaHCO3 | Ingredients for making bread |
| Carbon dioxide | CO2 | As a refresher on soft drinks |
| Aspirin | C9H8O4 | To reduce pain |
| Magnesium hydroxide | Mg(OH)2 | Antidote for gastric acid pain |
| Hydrochloric acid | HCl | Metal cleaners and hard water included |
| Sodium chloride | NaCl | As table salt |
| Sodium hydroxide | NaOH | For raw materials for soap making |
| sucrose | C12H22O11 | Food sweetener |
| Sulfuric acid | H2SO4 | For battery water |
| Urea | CO(NH2)2 | Plant fertilizer |
Knowing What Atoms Are
The existence of atoms, of course, cannot be separated from the discussion of molecules and compounds.
The concept of the atom, aka the smallest particle in an object, was first coined by Democritus.
According to him, all matter can be broken down into the smallest particles, which cannot be
divided further, that is what is called an atom. As the times progress, science will also
develop so that the existence of elementary particles of an atom is discovered, namely in the form of
protons, electrons and neutrons. These elementary particles are what make up atoms.
These elementary particles have a positive charge and a negative charge, but some are not charged, while
the mass is different. Protons usually have a positive charge and electrons have a negative
charge, while neutrons are neutral. This is because the proton has joined with the electron, so
that its nature will change to be neutral. Each of these elementary particles has its own
properties, namely:
| Atom | Sign | Load | Mass (grams) | Mass (ama) |
| Proton | P | +1 | 1.67252 x 10-24 | 1.00727663 |
| Neutrons | n | 0 | 1.67482 x 10-24 | 1.0086654 |
| Electron | e | -1 | 9.1091 x 10-28 | 0.000548597 |
Sinaumed’s must have understood that in terms of size, atoms are difficult to see with the naked eye
because they are so small. However, thanks to very sophisticated equipment in the form of a
microscope, we can know that the atom is approximately less than one part 10 billionths of a millimeter
in size! Likewise with other particles such as electrons which turn out to have a size of
approximately 100,000 times smaller than atoms! Wow, how tiny!
Proton
Protons are particles that have a positive charge and are found in the nucleus of an atom.
This proton is usually denoted by the letter P and its mass is 1 amu (atomic mass unit).
The charge on a proton is +1 which is also equal to 1.602 x 10-19 coulombs. Each
element must have certain atoms with an unequal number of protons. For example, hydrogen has
one proton. Then there is lithium, which has three protons. Then, there is also
sodium which has a proton number of about eleven, and so on.
Neutrons
The word neutron comes from the Latin word neutral , which means ‘has no charge’.
Meanwhile, the symbol for a neutron is n. The mass possessed by a neutron is
equivalent to 1 amu (atomic mass unit). Example: helium has two neutrons.
Then, there is also lithium which has three neutrons. There is also sodium which
has as many as eleven neutrons, and there are many more.
Electron
The constituent particles of an object with the lightest mass are electrons. The mass of an
electron is only 1/1.840 amu (atomic mass unit). For this reason, electrons are often
considered to be massless. However, the electron has a negative charge which is equivalent to
1.602 x 10-19 coulombs.
Dalton’s Atomic Theory
In 1803, a physicist and chemist named John Dalton proposed a theory which confirmed that matter must
consist of atoms. Based on this theory, it was concluded that the atom is the smallest part of
the element. Atoms tend to have neutral properties alias not electrically charged.
Well, in the atomic theory that was sparked by Dalton, it contains four important things in the
form of:
- All matter is composed of the smallest particles called atoms.
- Atoms cannot be created, split, or divided into smaller parts.
- Atoms of the same element have the same properties and mass.
- Atoms of different elements have different properties and masses.
How to Number Atoms and Their Masses
Does Sinaumed’s realize that an atom is not necessarily written in the alphabet like writing in general?
Yep, this is because an atom has unique properties and masses that distinguish it from other
atoms. The number of protons and neutrons contained in the atomic nucleus will later be
interconnected and usually their number will be the same. The masses of protons and
neutrons are also almost the same, and their sum is also almost the same as the mass of the atom.
While the mass of the electron is so small that it doesn’t contribute much to the overall
atomic mass. Well, here is the numbering of the atoms and their mass.
a) Atomic Number (Z)
The number of protons contained in an atom is called the atomic number, which will later be given the
letter Z. This atomic number characterizes an element. Since the atom is neutral, the number of
protons will equal the number of electrons. So, the atomic number will also indicate the number
of electrons.
The atomic number will usually be written slightly downwards, before the element symbol.
Example: the oxygen atom has 8 protons and 8 electrons, then the writing of the oxygen atom is
8.
b) Mass Number (A)
Previously, it was explained that the mass of an atom is very small, it can even be considered zero.
Therefore, the mass of the atom will be determined by the mass of the atomic nucleus, namely in the
form of protons and neutrons. The sum of the masses of protons and neutrons is called the mass
number, which is almost the same as the atomic mass.
Example: the oxygen atom has an atomic number of 8 and a mass number of 16. So the oxygen atom contains 8
protons and 8 neutrons. The writing will be
Know What Molecules Are
Molecule is a neutral particle consisting of the presence of two or more atoms, both atoms of the same kind
or atoms that are different. In its development, molecules are divided into 2 types, namely
monatomic molecules and polyatomic molecules.
a) Monatomic Molecules
That is a molecule consisting of one atom only. For example noble gas molecules (He, Ne, Ar,
Kr, Xe, and Rn)
b) Polyatomic Molecules
That is a molecule consisting of more than 1 atom. In this type of molecule, it is further
divided into several types, namely:
- Elemental molecules, namely polyatomic molecules consisting of atoms of the same kind.
Can be diatomic such as O2, N2, and C12; or be tetraatomic like P4;
it can also be octaatomic like S8. - Compound molecules, which are polyatomic molecules made up of different atoms.
Examples of Element Molecules and Their Benefits
| Elemental Molecules | Chemical Formulas | Benefit |
| Hydrogen Gas | H2 | Light manufacture |
| Oxygen gas | O2 | Respiratory system of living things |
| Nitrogen gas | N2 | Fertilizer manufacture |
| Chlorine gas | cl2 | Paper making |
| Iodine | I2 | Antiseptic and wound medicine |
| Phosphor | P4 | Matchmaking |
| Sulfur | S8 | As an itch remedy |
Examples of Compound Molecules and Their Benefits
| Compound Molecules | Chemical Formulas | The benefits |
| Acetic acid | CH3COOH | As food vinegar |
| Ammonia | NH3 | As a plant fertilizer |
| Ascorbic acid | C6H8O6 | As vitamin C for the body |
| Calcium carbonate | CaCO3 | Building material |
| Baking soda | NaHCO3 | Ingredients for making bread |
| Carbon dioxide | CO2 | As a refresher on soft drinks |
| Aspirin | C9H8O4 | To reduce pain |
| Magnesium hydroxide | Mg(OH)2 | Antidote for gastric acid pain |
| Hydrochloric acid | HCl | Metal cleaners and hard water included |
| Sodium chloride | NaCl | As table salt |
| Sodium hydroxide | NaOH | For raw materials for soap making |
| sucrose | C12H22O11 | Food sweetener |
| Sulfuric acid | H2SO4 | For battery water |
| Urea | CO(NH2)2 | Plant fertilizer |
Get to Know What Ions Are
Ions are actually atoms or groups of atoms that are electrically charged. These ions will
usually consist of both cations and anions. Cations are ions with a positive charge, while
anions are ions with a negative charge. These cations and anions will later combine in certain
and fixed proportions to form a neutral ionic compound. An example of an ion that is a
combination of cations and anions is table salt (sodium chloride), which is a Na+ cation with a Cl-
anion.
Examples of Cations and Anions in Ions
Cation Ions
| Na+ | Sodium |
| K+ | Potassium |
| Fe2+ | Iron(II) or ferrous |
| Fe3+ | Iron(III) or ferric |
| Cu+ | Copper (I) or cupro |
| Cu2+ | Copper(II) or cupric |
| NH4+ | Ammonium |
| H3O+ | Hydronium |
Anions Ions
| OH- | Hydroxide | NO3- | Nitrate |
| Cl- | chloride | NO2- | Nitrite |
| Br- | Bromide | SO42- | Sulfate |
| I- | Iodide | SO32- | Sulfites |
| CN- | Cyanide | PO43- | Phosphate |
| S2- | Sulfide | HPO42- | Hydrogen phosphate |
| NH2 | Amida | H2PO4- | Dihydrogen phosphate |
| ClO4- | Perchlorate | ClO3- | chlorate |
| ClO2- | chlorite | ClO- | hypochlorite |
| MnO42- | Manganate | SiO44- | Silicate |
| O22- | Peroxide |
Application of Atoms, Ions and Molecules in
Chemical Products
1. Detergent and Soap Products
The molecules in detergent products have nonpolar tails which will later be attracted to oil and grease.
Then it is the polar head that makes it soluble in water.
2. Urea Fertilizer
Does Sinaumed’s often think about why urea fertilizer can increase fertility in plants? This is
because urea fertilizer has a molecular formula in the form of CO(NH2)2. Of course, this
element is important in the urea itself and what plays a role in nourishing plants is Nitrogen (N).
This element also plays a major role as a constituent of protein as well as the formation of
chlorophyll.
If there is a lack of nitrogen, later the plants will appear yellowish because the amount of chlorophyll in the
leaves is also reduced.
- Sulfuric Acid in the Battery
Actually, the working principle of the battery is closely related to the formation of ions in solution.
The battery is composed of several cells, where each cell is an electric current generating unit
which can produce a voltage of 2 volts. Each of these cells is composed of a weighing plate
(Pb) as the negative pole, while lead dioxide (PbO2) as the positive pole. The two metals will
then be dipped in a solution of sulfuric acid (H2SO4).
- Battery
The battery has a zinc (Zn) layer that functions as a negative pole, which layer will also be covered by a
steel sheath. Well, if a battery is opened, there will be one carbon rod in it.
The carbon serves as the positive pole. The carbon is placed in the center of the cell
and connected to a metal protrusion on the outside of the top of the battery. While the space
between the carbon rod and the zinc layer will be filled with ammonium chloride paste.
So, that’s a description of what a compound molecule is and an example of a compound molecule that is often
used in everyday life. Does Sinaumed’s often use “products” from compound molecules?