Multiple Choice
An ion has 104 electrons, 157 neutrons, and 102 protons. What is the mass number of this ion?
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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 is the number of electrons in a neutral atom of scandium (Sc)?
A
12
B
21
C
44
D
23
Verified step by step guidance1
Recall that in a neutral atom, the number of electrons is equal to the number of protons.
Identify the atomic number of scandium (Sc) from the periodic table, which represents the number of protons in the nucleus.
Note that scandium has an atomic number of 21, meaning it has 21 protons.
Since the atom is neutral, the number of electrons must also be 21 to balance the positive charge of the protons.
Therefore, the number of electrons in a neutral atom of scandium is 21.
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