Introduction

In chemistry, the composition of atoms is essential to understanding the behavior of elements. Two important terms in this field are atomic mass and atomic number. They are often confused with each other, but in reality they have very different meanings.

Atomic number

The atomic number is the number of protons found in the nucleus of an atom. This is a very important value for chemists, as it determines the number of electrons surrounding the nucleus and, therefore, the chemical properties of the element. The atomic number is usually represented by the letter Z. Each element has a unique atomic number that distinguishes it from the others on the periodic table.

Atomic mass

Atomic mass is the sum of the protons and neutrons contained in the nucleus of an atom. It is represented by the letter A. Unlike the atomic number, the atomic mass is not an integer, since isotopes of an element can have different numbers of neutrons. Therefore, the atomic mass is calculated as the weighted average of the masses of all existing isotopes of an element. In nature. The unit of measurement for atomic mass is the atomic mass unit (amu).

Differences

In short, the atomic number is the number of protons an atom has, while the atomic mass is the sum of protons and neutrons in the nucleus of the atom. The atomic number is an integer what is used to classify elements and determine the chemical properties of an atom. Instead, the atomic mass is a decimal value that represents the weighted average of the isotopes of an element.

Example

Take hydrogen as an example. Hydrogen has an atomic number of 1. which means that It has 1 proton in its nucleus. However, there are three isotopes of hydrogen: hydrogen-1 (no neutrons), hydrogen-2 (1 neutron), and hydrogen-3 (2 neutrons). The atomic mass of hydrogen is approximately 1.008 amu, meaning its most common isotope is hydrogen-1.

Conclusion

In conclusion, atomic mass and atomic number are two different terms, but both are important to understand the structure of atoms and the properties of elements. It is important not to confuse them with each other and understand how they relate to each other in order to better understand the chemistry.

References:

• Chemistry LibreTexts. "Atomic Mass and Atomic Number." Recovered from: https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Atomic_and_Molecular_Properties/Atomic_and_Molecular_Structure/Atomic_Mass_and_Atomic_Number
• American Chemical Society. «What's the difference between atomic mass and atomic weight?» October 2, 2017. Retrieved from: https://www.acs.org/content/acs/en/education/resources/highschool/chemmatters/past-issues/2017-2018/october-2017/whats-difference-atomic-mass-weight.html

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