Multiple Choice
Which type of isotope undergoes radioactive decay?
2
views
4. Atoms and Elements
Isotopes
Struggling with Introduction to Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which isotope is described by an atom with 11 protons and 12 neutrons?
A
(sodium-23)
B
(neon-23)
C
(sodium-22)
D
(magnesium-23)
Verified step by step guidance1
Identify the number of protons in the atom, which is given as 11. The number of protons defines the element's atomic number.
Recall that the element with atomic number 11 is sodium (Na). This means the atom is a sodium isotope.
Calculate the mass number of the isotope by adding the number of protons and neutrons: \(\text{mass number} = \text{protons} + \text{neutrons} = 11 + 12\).
Write the isotope notation by placing the element symbol (Na) with the mass number as a superscript: \(^{\text{mass number}}\mathrm{Na}\).
Compare the calculated mass number with the options to select the correct isotope, which is sodium-23.
Related Videos
Related Practice
