Open Question
Indicate if the atoms in each pair have the same number of protons, neutrons, or electrons. (4.4, 4.5)c. ⁴⁰₁₈Ar, ³⁹₁₇Cl
4. Atoms and Elements
Isotopes
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Which of the following answers give the correct number of subatomic particles for 
?
A
34 protons, 34 neutrons and 34 electrons
B
50 protons, 18 neutrons and 18 electrons
C
16 protons, 18 neutrons and 16 electrons
D
17 protons, 17 neutrons and 17 electrons
Verified step by step guidance1
Identify the element from the chemical symbol. The symbol 'S' represents sulfur.
Determine the atomic number from the lower number next to the symbol. The atomic number is 16, which indicates the number of protons in the nucleus of the sulfur atom.
The number of electrons in a neutral atom is equal to the number of protons. Therefore, sulfur has 16 electrons.
Determine the mass number from the upper number next to the symbol. The mass number is 34, which is the sum of protons and neutrons in the nucleus.
Calculate the number of neutrons by subtracting the atomic number from the mass number: 34 (mass number) - 16 (atomic number) = 18 neutrons.
