SCIENCE
PHYSICAL SCIENCES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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If the atomic mass of an element is 40, and its atomic number is 20, how many neutrons must it have?
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40
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20
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16.5
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0
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Explanation:
Detailed explanation-1: –In the question it is given that an element has a mass number of 40 and number of protons are 20.-We know that mass number = number of protons + number of neutrons.-Therefore the number of neutrons = 40 – 20 = 20 neutrons.
Detailed explanation-2: -An atom of the calcium-40 isotope has 20 neutrons in its nucleus.
Detailed explanation-3: -Calcium has 20 protons and 20 neutrons.
Detailed explanation-4: -Number of neutrons = 40 – 18 = 22.
There is 1 question to complete.