Question:
What is the mass number of the isotope lithium-7? Lithium has 3 protons. How many neutrons are in the isotope lithium-8?
Posted By Admin @ September 03, 2022
What is the mass number of the isotope lithium-7? Lithium has 3 protons. How many neutrons are in the isotope lithium-8?
The isotope of Lithium-7 has a mass number of 7. And the isotope of Lithium-8 has 5 neutrons.
Given data:
The number of protons in a lithium-7 isotope is, 3.
The mass number of an element is equal to to the number of protons inside its nucleus. Mathematically,
Mass number = number of protons + number of neutrons
Mass number of Lithium-7:
The nomenclature of "Element-X", where X is an abbreviation to indicate the mass number of the isotope.
Therefore, an isotope of Lithium-7 has a mass number of 7.
Number of neutrons in an isotope of lithium-8:
Lithium-8 has the mass number of 8. And we know that,
Mass number = number of protons + number of neutrons
Lithium is the third element of the periodic table, so its atomic number is 3, which means that it has 3 protons.
Then,
8 = 3 + number of neutrons
number of neutrons = 8 - 3
number of neutrons = 5
Therefore, an isotope of Lithium-8 has 5 neutrons.
Learn more about the mass number here: