How do scientists determine the number of neutrons in an isotope of an atom?
A. They find the number of protons.
B. They divide the atomic mass by two.
C. They add the number of

electrons and protons.
D. They subtract the atomic number from the atomic mass.

B. atomic number from mass number. Atomic number - mass number gives us the number of neutrons in an atom.

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Asked 10/22/2012 4:12:05 PM

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Find the difference.
8 – 12
A. –20
B. –4
C. 4
D. 20

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Updated 8/6/2014 6:31:03 PM

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The difference for 12 – (–17) is 29.

12-(-17)

=12+17

=29.

12-(-17)

=12+17

=29.

Added 8/6/2014 6:27:31 PM

This answer has been confirmed as correct, not copied, and helpful.

Confirmed by andrewpallarca [8/6/2014 6:31:13 PM], Rated good by andrewpallarca

Find the difference.
12 – (–17)
A. –29
B. –5
C. 5
D. 29
**Weegy:** The difference of 12 ? (?17) is: D. 29 **User:** Choose the correct answer.
Which expression has a value of 27?
A. –15 – (–12)
B. –25 – 2
C. 10 – 17
D. 16 – (– 11)
**Weegy:** D. 16 – (– 11)
seems to be closest answer. (More)

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Expert Answered

Asked 10/15/2012 12:46:29 PM

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Choose the correct answer.
Which expression has a value of 27?
A. –15 – (–12)
B. –25 – 2
C. 10 – 17
D. 16 – (– 11)
**Weegy:** D. 16 – (– 11). The expression 16 – (– 11) has a value of 27. (More)

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Asked 10/15/2012 1:01:15 PM

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What is the value of the expression q + 39 when q = –12?
A. –51
B. –27
C. 27
D. 51
**Weegy:** C. 27. If q is -12, then the value of -12 + 39 is 27. (More)

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Asked 10/15/2012 1:08:17 PM

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What is the value of the expression 1 – r – a when r = 20 and
a = 6?
A. –27
B. –25
C. –15
D. –13
**Weegy:** B. –25. If r is 20 and a is 6, then the value of 1 - 20 - 6 is -25. (More)

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Asked 10/15/2012 1:14:01 PM

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