# How to Find Out the Number of Neutrons in an Atom

Even though all atoms of the same element contain the same number of protons, the number of neutrons can vary. Knowing how many neutrons a particular atom has can help you determine whether the particle is regular in that element or an isotope, which will have too many or too few neutrons. Determining the number of neutrons in an atom is quite simple and requires no experiment. To calculate the number of neutrons in a regular atom or isotope, follow these instructions with a periodic table at hand.

## Steps

### Method 1 of 2: Finding the Number of Neutrals in a Common Atom

#### Step 1. Locate the element on the periodic table

For this example, let's look at the Os (Os), which is in the sixth row, from top to bottom.

#### Step 2. Find the atomic number of the element

This is usually the most visible number for a given element and is usually above the symbol for that element (in the table we're using, there's actually no other number listed). The atomic number is the number of protons of a single atom of that element.. The number of Os is 76, which means that an osmium atom has 76 protons.

#### Step 3. Find the atomic weight of the element

This number is usually found below the atomic symbol. Note that the table in this example is based on the atomic number only and does not list the atomic weight. This will not always be the case. Osmium has an atomic weight of 190, 23.

#### Step 4. Round the atomic weight to the nearest whole number to find the atomic mass

In our example, 190, 23 would be rounded to 190, resulting in an atomic mass of 190 for Osmium.

### Atomic mass is an average of the element's isotopes. Therefore, it is normally not an integer

#### Step 5. Subtract the atomic number from the atomic mass

Since the vast majority of an atom's mass is found in its protons and neutrals, subtracting the number of protons (ie, the atomic number) from the atomic mass will give you the calculated number of neutrons in the atom. The number after the decimal point generally represents a very small mass of electrons in the atom. In our example, this is: 190 (atomic mass) - 76 (number of protons) = 114 (number of neutrons).

#### Step 6. Remember the formula

To find the number of neutrons in the future, just use this formula:

• N = M - n.

• N = number of Neutrons.
• M = Matomic wing.
• n = atomic humerus.

### Method 2 of 2: Finding the Number of Neutrons in an Isotope

#### Step 1. Locate the element on the periodic table

For example, let's use the carbon-14 isotope. Since the non-isotopic form of carbon-14 is simply Carbon (C), find this element in the periodic table (in the second row).

#### Step 2. Find the atomic number of the element

This is usually the most visible number for a given element and is usually above the symbol for that element (in the table we're using, there's actually no other number listed). The atomic number is the number of protons of a single atom of that element.. The C is the number 6, which means that a carbon atom has 6 protons.

#### Step 3. Find the atomic mass

This is incredibly easy with isotopes, as they are named after their atomic mass. Carbon-14 has an atomic mass of 14. Once you find the atomic mass of the isotope, the process for finding the number of neutrons is the same as that used for common atoms.

#### Step 4. Subtract the atomic number from the atomic mass

Since the vast majority of an atom's mass is found in its protons and neutrals, subtracting the number of protons (ie, the atomic number) from the atomic mass will give you the calculated number of neutrons in the atom. The number after the decimal point generally represents a very small mass of electrons in the atom. In our example, this is: 14 (atomic mass) – 6 (number of protons) = 8 (number of neutrons).

#### Step 5. Remember the formula

To find the number of neutrons in the future, just use this formula:

• N = M - n.

• N = number of Neutrons.
• M = Matomic wing.
• n = atomic humerus.

## Tips

• Osmium, a solid metal at room temperature, derives its name from the Greek word for 'smell', "osme".
• Protons and neutrons make up almost the entire weight of the elements, while electrons and other miscellaneous particles represent negligible mass (approaching zero mass). Since a proton has approximately the same weight as a neutral and the atomic number represents the number of protons, we can simply subtract the number of protons from the total mass.
• If you're not sure which number is which on the periodic table, just remember that it's usually made around the atomic number (ie, the number of protons), which starts with 1 (Hydrogen) and goes up one unit per turn, from left to right, ending in 118 (Ununóctio). This is because the number of protons in an atom determines what that atom is, facilitating the organization of the elemental characteristic (for example, an atom with 2 protons will always be Helium, as well as another atom with 79 protons will always be Gold).