Question

there are two common isotopes of the element lithium. the first isotope has 3 protons and 3 neutrons. the second isotope has 3 protons and 4 neutrons. using the hyphenated notation, what are the names of these two isotopes, respectively? a lithium-7 and lithium-8 b lithium-3 and lithium-4 c lithium-6 and lithium-7 d lithium-9 and lithium-10

Explanation:

Step1: Calculate mass number of first isotope

Mass number = protons + neutrons. For the first isotope with 3 protons and 3 neutrons, mass number = 3 + 3 = 6.

Step2: Calculate mass number of second isotope

For the second isotope with 3 protons and 4 neutrons, mass number = 3+ 4 = 7.

Step3: Determine hyphenated - notation names

In hyphenated notation, the name is element - mass number. So the names are lithium - 6 and lithium - 7.

Answer:

C. lithium - 6 and lithium - 7