Multiple Choice
What is the chemical symbol for magnesium?
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2. Atoms & Elements
Periodic Table: Element Symbols
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Which neutral element has 89 electrons?
A
Actinium (Ac)
B
Thorium (Th)
C
Francium (Fr)
D
Radium (Ra)
Verified step by step guidance1
Recall that a neutral atom has an equal number of protons and electrons. Therefore, the number of electrons corresponds to the atomic number of the element.
Identify the element whose atomic number is 89, since the atom has 89 electrons and is neutral.
Look up the periodic table or use your knowledge of element atomic numbers to find which element has atomic number 89.
Confirm that the element with atomic number 89 is Actinium (Ac).
Verify that the other options (Thorium, Francium, Radium) have different atomic numbers: Thorium (90), Francium (87), Radium (88), so they do not match 89 electrons.
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