Multiple Choice
How many electrons does an oxygen atom need to gain in order to achieve a stable, noble gas electron configuration?
3
views
2. Atoms & Elements
Ions
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
Which of the following pairs of ions have the same total number of electrons?
A
Ca^{2+} and S^{2-}
B
Na^+ and F^-
C
Mg^{2+} and O^{2-}
D
K^+ and Cl^-
Verified step by step guidance1
Recall that the total number of electrons in an ion is equal to the number of protons in the neutral atom minus the charge of the ion (subtract electrons for positive charge, add electrons for negative charge).
Determine the atomic number (number of protons) for each element involved: Ca (20), S (16), Na (11), F (9), Mg (12), O (8), K (19), Cl (17).
Calculate the total electrons for each ion by adjusting the atomic number according to the ion's charge. For example, for Ca^{2+}, electrons = 20 - 2 = 18.
Compare the total electrons of each pair to see which pairs have the same number of electrons.
Identify the pair(s) with equal total electrons, which means they are isoelectronic (having the same electron configuration).
Related Videos
Related Practice
