Question

how many neutrons does this isotope have? 48

1. type the correct answers in the blanks below.

identify the following from this isotope. $_{10}^{21}ne$
name of isotope: ___
atomic mass number: ___
atomic number: ___
number of protons: ___
number of neutrons: ___

1. choose the best answer. use significant figures to solve.

rubidium is known to have two isotopes - $^{87}rb$ and $^{85}rb$. the abundance of $^{85}rb$

Explanation:

Step1: Recall isotope notation meaning

The notation $_{10}^{21}Ne$ has the atomic number (number of protons) as the sub - script and the atomic mass number as the super - script.

Step2: Identify name of isotope

The element is neon (Ne), and with a mass number of 21, it is called neon - 21.

Step3: Determine atomic mass number

The atomic mass number is the super - script in the isotope notation, so it is 21.

Step4: Find atomic number

The atomic number is the sub - script in the isotope notation, so it is 10.

Step5: Calculate number of protons

The number of protons is equal to the atomic number, so it is 10.

Step6: Calculate number of neutrons

The number of neutrons is the atomic mass number minus the atomic number. So, $21 - 10=11$.

Answer:

Name of isotope: neon - 21
Atomic mass number: 21
Atomic number: 10
Number of protons: 10
Number of neutrons: 11