Multiple Choice
Given the following atoms and their atomic masses: Hydrogen (1.008 u), Carbon (12.01 u), Oxygen (16.00 u), and Iron (55.85 u), which atom has the highest atomic mass?
34
views
2. Atoms & Elements
Atomic Mass
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
What is the mass number of an ion that has 105 electrons, 157 neutrons, and a +1 charge?
A
263
B
261
C
105
D
262
Verified step by step guidance1
Recall that the mass number (A) of an atom or ion is the sum of the number of protons (Z) and neutrons (N): \(A = Z + N\).
Understand that the number of electrons is related to the number of protons and the charge of the ion. For an ion with charge +1, the number of electrons is one less than the number of protons: \(\text{electrons} = Z - 1\).
Use the given number of electrons (105) and the charge (+1) to find the number of protons: \(Z = \text{electrons} + 1 = 105 + 1\).
Use the given number of neutrons (157) and the calculated number of protons to find the mass number: \(A = Z + N = (105 + 1) + 157\).
Sum the values to express the mass number, which represents the total number of protons and neutrons in the ion.
Related Videos
Related Practice
