Textbook Question
In an endothermic chemical reaction, do the products have more mass, less mass, or the same mass as the reactants? Explain.
21. Nuclear Chemistry
Intro to Radioactivity
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The mass number of an isotope is
A
the number of protons in the nucleus.
B
the number of neutrons in the nucleus.
C
the number of electrons in the nucleus.
D
the sum of the number of protons and neutrons in the nucleus.
E
the sum of the number of protons and electrons in the nucleus.
Verified step by step guidance1
Understand that the mass number of an isotope is a key concept in chemistry, representing the total number of protons and neutrons in the nucleus of an atom.
Recall that protons are positively charged particles found in the nucleus, and they define the atomic number of an element.
Remember that neutrons are neutral particles also located in the nucleus, and they contribute to the mass of the atom but not its charge.
Recognize that electrons are negatively charged particles that orbit the nucleus and do not significantly contribute to the mass number.
Combine the number of protons and neutrons to determine the mass number of an isotope, as the mass number is the sum of these two types of particles in the nucleus.
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