Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which is the correct chemical formula for the ionic compound formed from aluminum (Al) and selenium (Se) atoms?
A
Al3Se2
B
AlSe
C
Al2Se3
D
AlSe2
Verified step by step guidance
1
Identify the charges of the ions formed by aluminum and selenium. Aluminum typically forms a +3 charge (Al^{3+}), and selenium typically forms a -2 charge (Se^{2-}).
Determine the ratio of aluminum ions to selenium ions needed to balance the total positive and negative charges so that the compound is electrically neutral.
Set up the charge balance equation: (number of Al ions) \times (+3) + (number of Se ions) \times (-2) = 0.
Find the smallest whole number ratio of Al to Se that satisfies the charge balance. This involves finding the least common multiple of the charges 3 and 2, which is 6.
Write the chemical formula using the ratio found: the number of Al atoms corresponds to the number of Al^{3+} ions, and the number of Se atoms corresponds to the number of Se^{2-} ions, resulting in Al_{2}Se_{3}.