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# Atomic Mass Calculator

Provide the number of protons (Z) and neutrons (N) and the calculator will calculate the atomic mass.

Number of Protons (Z)

Number of Neutrons (N)

Table of Content
 1 What is Atomic Mass? 2 Atomic Mass Formula: 3 How to Find Atomic Mass? 4 Find Atomic Mass for a Single Atom: 5 Find the Atomic Mass of a Natural Sample: 6 Find the Atomic Mass of a Given Ratio of Isotopes: 7 Atomicity Table of Some Elements: 8 Why do atoms need neutrons? 9 How Many Grams are There in One Mole? 10 How to calculate the atomic mass of an isotope? 11 How do atoms exist?
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An online atomic mass calculator helps you to determine the atomic mass, mass number and atomic symbol. To determine the atomic mass, it is important to know whether a specific sample is an atom, atomic isotopes in a specific ratio, or a natural sample of elements. In this content, you can learn three different ways of how to find average atomic mass, what is atomicity, Ions, Isotopes with the help of several examples and tables.

## What is Atomic Mass?

Atomic mass is defined as the weight/mass of an atom of the chemical element. It has the masses of three different subatomic particles, such as electrons, protons, and neutrons; it is expressed in a unified atomic mass unit, expressed by the unit symbol “U”. Generally, the atomic mass is 1/12 of the mass of carbon 12. Atomic mass can solve stoichiometric problems and calculate the average mass of elements and molecules.

### Atomic Mass Formula:

Although you can specify atomic mass in kilograms, atomic mass is usually expressed in atomic mass units (u), also known as Daltons (Da). An atomic mass unit (Dalton) is 1/12 of the mass of a carbon atom. Therefore, the unit of atomic mass is $$1.66 * 10^-27 kg$$.
How to calculate atomic mass? According to atomic mass definition, find a reasonable approximation of the atomic mass of an atomic mass unit, we can add the number of protons and neutrons together so that the formula for atomic mass is:
atomic mass (u) ≈ number of neutrons + number of protons
This atomic mass equation is similar to the formula of mass number:
$$A = N + Z$$
where:
A = mass number
Z = number of protons
N = number of neutrons

### How to Find Atomic Mass?

In order to find the atomic mass and symbol, you can use an online atomic mass calculator. Otherwise, you can also use the following techniques for determining the atomic mass manually:

### Find Atomic Mass for a Single Atom:

Since the total mass of neutrons and protons represents the total mass of a given atom, the atomic mass of an atom can be calculated by substituting the total number of neutrons and the total number of protons of that isotope.
The number of protons in an atom is equal to its atomic number. For example, the atomic number of oxygen (O) is 8, so the number of protons in an oxygen atom is 8 that describes which isotope of an atom belongs to the total number of neutrons.

Example:

How to find the atomic mass of an oxygen molecule with 9 neutrons.

Solution:

You can use an average atomic mass calculator for calculating the atomic mass of oxygen (O). However, if you want to do this manually then add the atomic number of oxygen and the number of neutrons in a given isotope.
Atomic number of oxygen = 8
The total number of neutrons in a given isotope = 9
The atomic mass of oxygen atom = 8 + 9 = 17

#### Find the Atomic Mass of a Natural Sample:

The atomic mass of a given sample can be easily found in the periodic table of the elements. To find an element in the periodic table, you need to know the symbol of the element or its atomic number. Once the required data is obtained, it can be compared with the periodic table, which displays the atomic mass of samples in atomic mass units.

#### Find the Atomic Mass of a Given Ratio of Isotopes:

If the sample is a mixture of isotopes of a specific element in different percentages, then the following method can be used:
Step 1: Multiply the atomic mass of the isotope by its percentage and divide the result by 100.
Step 2: Add the obtained values in step 1 For each isotope specified in the sample.
Example: How to calculate atomic weight of a given chlorine sample when two isotopes are mixed. The atomic mass of the first isotope is 34.96885, and the abundance is 75.78%. The atomic mass of the second isotope is 36.96590, and the abundance is 24.22%.
Calculating atomic mass with average atomic mass formula:

Step 1: (%Abundance / 100) x (atomic mass of each isotope)
$$0.7578 * 34.96885 = 26.50$$

$$0.2422 * 36.96590 = 8.95$$
Now, determine the value of a given sample quality:
$$8.95 + 26.50 = 35.45$$
Use our atomic weight calculator for quickly calculating the atomic weight of an element. Therefore, the atomic mass of the chlorine sample is 35.45.

However, an online Molar Mass Calculator helps you to determine the molecular weight, hill notation, nominal, and monoisotopic mass for given chemical formulas.

### Atomicity:

Monoatomic: When a molecule consists of one atom, it is called a monoatomic molecule. Usually, noble gases or called monoatomic. For example: neon (Ne), helium (He), argon (Ar), krypton (Krypton), Randon (Rn), xenon (Xe).
Diatomic molecule: When a molecule is composed of a diatomic molecule: When a molecule is composed of its two atoms, it is called a diatomic molecule. For example Oxygen (O2), Nitrogen (N2), Hydrogen (H2), Chlorine (Cl2)
Triatomic: When a molecule is formed by three atoms, it is called a triatomic molecule. For example ozone molecule (O3)
Tetra-atomic: When the molecule is composed of a combination of four atoms, it is called a tetra-atomic molecule. For example molecule of phosphorus (P4)
Polyatomic: when the molecule is composed of the combination of four atoms is called a polyatomic molecule. For example a sulfur molecule (S8)

#### Atomicity Table of Some Elements:

You can find the symbol of any element by substituting the number of protons and neutrons in the average atomic mass calculator or you can use a table for this purpose.

 Name Atomicity Symbol Argon Monoatomic Ar Helium Monoatomic He Oxygen Diatomic O2 Hydrogen Diatomic H2 Nitrogen Diatomic N2 Chlorine Diatomic Cl2 Phosphorus Tetra-atomic P4 Sulphur Poly-atomic S8

### Ions:

If you ask yourself how to calculates atomic mass in different units and atomic numbers then our atomic mass calculator is perfect for you. The atoms of different elements exist in the forms, so the negatively or positively charged atoms or molecules of elements are called ions.
example: Potassium ion (K +), chloride ion (Cl-), sodium ion (Na +), fluoride ion (F-), etc.

Cation: Positively charged ions are called cations.

examples: potassium ion (K +), hydrogen ion (H +), sodium ion (Na +), etc.

Anion: Negatively charged ions are called anions.

For example: fluoride ion (F-), carbonate ion (CO3-), chloride ion (Cl-), etc.

Monoatomic ion: Ions formed by one atom is called monoatomic ions.

example: potassium ion (K +), fluoride ion (F-), sodium ion (Na +), chloride ion (Cl-), etc.

Polyatomic ion: An ion formed by two or more atoms is called a polyatomic ion.
example: ammonium ion (NH4 +), carbonate ion (CO3–), hydroxide ion (OH–), etc.

### Isotopes:

The name of a specific isotope of any element is written by placing the mass superscript from the left side of the element symbol. The atomic number is written as the subscript in front of the symbol, but this number identifies the identity of the element, so it is often omitted.

For example, magnesium (Mg) exists as a mixture of three isotopes, each of which has an atomic number of 12 and a mass number of 24, 25, and 26, respectively. These isotopes can be identified as 24Mg, 25Mg and 26Mg. These are mass numbers that can be calculated by the atomic mass calculator and can be symbolized according to this reading.

For example, 24Mg is pronounced ” magnesium 24″ and can be written as “Mg-24” or ” magnesium-24″. 25Mg is pronounced ” magnesium 25″ and can be written as “Mg-25” or “magnesium-25”. All magnesium atoms in the nucleus have 12 protons. The only difference between them is that the magnesium-24 atom in the nucleus has 12 neutrons, the magnesium-25 atom has 13 neutrons, and the magnesium-26 atom has 14 neutrons.

 Element Symbol Atomic Number Number of Protons Number of Neutrons Mass (AMU) % Natural Abundance hydrogen /( ^1_1H \) (protium) 1 1 0 1.0078 99.989 /( ^2_1H \) (deuterium) 1 1 1 2.0141 0.0115 /( ^3_1H \) (tritium) 1 1 2 3.01605 — (trace) helium /( ^3_2He \) 2 2 1 3.01603 0.00013 /( ^4_2He \) 2 2 2 4.0026 100 lithium /( ^6_3Le \) 3 3 3 6.0151 7.59 /( ^7_3Le \) 3 3 4 7.0160 92.41 beryllium /( ^9_4Be \) 4 4 5 9.0122 100 boron /( ^10_5B \) 5 5 5 10.0129 19.9 /( ^11_5B \) 5 5 6 11.0093 80.1 carbon /( ^12_6C \) 6 6 6 12.0000 98.89 /( ^13_6C \) 6 6 7 13.0034 1.11 /( ^14_6C \) 6 6 8 14.0032 — (trace) nitrogen /( ^14_7N \) 7 7 7 14.0031 99.63 /( ^15_7N \) 7 7 8 15.0001 0.37 oxygen /( ^16_8O \) 8 8 8 15.9949 99.757 /( ^17_8O \) 8 8 9 16.9991 0.038 /( ^18_8O \) 8 8 10 17.9992 0.205 fluorine /( ^19_9F \) 9 9 10 18.9984 100 neon /(^20_10Ne\) 10 10 10 19.9924 90.48 /(^21_10Ne\) 10 10 11 20.9938 0.27 /(^22_10Ne\) 10 10 12 21.9914 9.25

### Why do atoms need neutrons?

Generally, the atom has a neutral charge. However, all the positive charges are concentrated in the centre of the proton. Just as charges repel, there is a force that tries to destroy the core or nucleus of an atom. The opposite of this force is the strong nuclear force that exists between neutrons and protons. Therefore, the total amount of strong nuclear attraction can be increased by adding neutrons to prevent atomic destruction.

However, an online Mole Calculator helps you to calculate the number of moles of a substance based on the molecular weight and the quantity of that material.

## How Atomic Mass Calculator Works?

An online atomic weight calculator determines the atomic mass by the following steps:

### Input:

• First, Enter the number of protons (Z) and the number of neutrons (N).
• Hit the “Calculate Atomic Mass”.

### Output:

The atom calculator will calculate:

• Atomic mass unit
• SI units of atomic mass,
• Mass number
• Atomic Symbol
• Atomic stability

## FAQ:

### What is the fractional percent?

The fractional percentage is the total percentage of a given isotope in the substance.

### How Many Grams are There in One Mole?

The molar mass of a compound or an element is the mass per mole of the substance. The value is given in g/mole or grams/mole. You can determine the molecular weight by looking up the numbers under the element names in the periodic table. For example, the chlorine molar mass is 35.45 grams/mol.

### Why is it not possible to see an atom with naked eyes?

Due to its extremely small size (atomic radius is about 10-10 meters), it is impossible to see atoms with the naked eye.

### How to calculate the atomic mass of an isotope?

For any given isotope, the total sum of the numbers of neutrons and protons in the nucleus is called the mass number of an element. This is because each neutron and each proton weigh one atomic mass unit. Therefore, an online average atomic mass calculator can find the atomic mass of any element by adding the number of neutrons and protons and multiplying by 1 atomic mass unit.

### What are the Molecules of compounds?

When a molecule is built by the combination or mixture of two or more atoms of elements, it is called a molecule of the compound.

Molecules of Different Compounds:

 Compound Combining Elements Water (H2) Oxygen, Hydrogen Ammonia (NH3) Hydrogen, Nitrogen Carbon dioxide (CO2) Oxygen, Carbon Hydrogen Chloride (HCl) Chlorine, Hydrogen Methane (CH4) Hydrogen, Carbon Ethane (C2H6) Hydrogen, Carbon Sodium Chloride (NaCl) Chlorine, Sodium Copper Oxide (CuO) Oxygen, Copper

### How do atoms exist?

The atoms of most elements exist in the form of molecules or ions because they are the most reactive, such as oxygen, hydrogen, and chlorine. However, the atoms of some non-reactive elements exist in a free state in nature such as neon, helium, argon, etc.

### What is the atomic mass of n in different units?

In order to find atomic mass of Nitrogen (N), you can use a proton-neutron electron calculator, which is a 14.0067 atomic mass unit.
Where,
Atomic Number = 7
Mass of proton in kg = $$1.6726231(10)E^{-27}$$
Mass of proton in amu = 1.007276470
Mass of neutron in amu = $$1.6749286(10)E^{-27}$$

### How an atom is stable?

An atom is stable when the force among different particles balanced the nucleus. On the other side, if the force is unbalanced among the particles of an atom then an atom is unstable.

### How many atoms are in a person?

Unless you look at how many atoms there are, it is difficult to understand how small the atoms that make up your body. An adult is composed of approximately 7,000,000,000,000,000,000,000,000,000 (7 octillion) atoms.

### Can you destroy an atom?

Atoms cannot be destroyed or created, and they are indestructible; they cannot be broken down into smaller parts. This is based on the law of conservation of mass. It was later discovered that atoms can be broken down into smaller pieces.

## Conclusion:

Use this online atomic mass calculator to find the stability, atomic symbol, mass number, and atomic mass in different units. The atomic mass of an element is the weighted average of the atomic masses of the naturally occurring isotopes of that element. This recommendable online calculator can find the atomic mass of any element by adding the number of neutrons and protons that is more beneficial for both students and tutors.

## Reference:

From the source of Wikipedia: Relative isotopic mass, Similar terms for different quantities, Mass defects in atomic masses, The ratio of atomic mass to mass number, Relationship between atomic and molecular masses.

From the source of Lumen Learning: Atomic Masses and Percent Abundances of Some Natural Isotopes, Calculating Atomic Mass, Percent natural abundance.

From the source of Khan Academy: Atomic number, Atomic mass, and Relative atomic mass, Isotopes and radioactive decay, isotope’s half-life.

From the source of Libre Text: Atomic mass unit and average atomic mass, Isotopes, Nuclear Compositions of Atoms of the Very Light Elements, Calculation of Percent Abundance, The Mole, Mass of one mole of elements.