Mass Number: What is it and why does it matter?
What is the mass number of an element?
The mass number is:
A) The average charge of all ions of the element.
B) The sum of the atomic numbers of all the isotopes.
C) The average atomic mass of the element.
D) The sum of the atomic masses of all the isotopes.
Final answer: The mass number is most similar to the average atomic mass of the element, which is a weighted average of all the isotopes taking into account their individual masses and abundances.
Answer:
The mass number of an element is the sum of the number of protons and neutrons in the nucleus of an atom. It is represented by the symbol 'A'.
In the given data, the correct choice is C) The average atomic mass of the element.
The mass number is an important concept in chemistry as it helps in identifying and differentiating between different isotopes of an element. Isotopes are atoms of the same element with a different number of neutrons. The mass number gives us information about the overall mass of an atom, which is crucial for various chemical calculations.
For example, in the case of hydrogen, there are three isotopes: protium with a mass number of 1, deuterium with a mass number of 2, and tritium with a mass number of 3. By knowing the mass number, we can calculate the atomic mass of each isotope and determine the average atomic mass of hydrogen as an element.
The average atomic mass of an element is calculated by taking the weighted average of the atomic masses of all the isotopes, considering their natural abundances. This average atomic mass is found on the periodic table for each element and helps chemists in various calculations, such as determining stoichiometry in chemical reactions.
Understanding the concept of mass number and average atomic mass is fundamental in chemistry and is essential for students and professionals working in the field of science.