Textbook Question
For each representation of a nucleus A through E, write the atomic symbol and identify which are isotopes. (4.4, 4.5) Proton (red) Neutron (white)a.
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4. Atoms and Elements
Isotopes
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Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
An atom with 3 protons and 4 neutrons is which isotope?
A
Beryllium-7 ()
B
Helium-7 ()
C
Lithium-7 ()
D
Lithium-6 ()
Verified step by step guidance1
Identify the element by the number of protons. The number of protons defines the atomic number, which determines the element. Here, the atom has 3 protons.
Recall the periodic table to find which element has an atomic number of 3. This element is Lithium (Li).
Determine the mass number of the isotope by adding the number of protons and neutrons together. Mass number = protons + neutrons = 3 + 4.
Write the isotope notation using the element symbol and the mass number as a superscript. This will be in the form \(\text{Element}^{\text{Mass Number}}\), for example, \(\text{Li}^7\).
Match the isotope notation to the given options to identify the correct isotope name and symbol.
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