A sample of chlorine gas from a chemical plant in Trinidad contains two isotopes: chlorine-35 and chlorine-37. Both isotopes have 17 protons. What is the difference between these isotopes?

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Question

A sample of chlorine gas from a chemical plant in Trinidad contains two isotopes: chlorine-35 and chlorine-37. Both isotopes have 17 protons. What is the difference between these isotopes?

Accepted Answer

Number of neutrons — Award 1 mark for C. Cl-35 has 18 neutrons (35-17) while Cl-37 has 20 neutrons (37-17). A is incorrect because isotopes have the same number of protons. B is incorrect because neutral atoms have equal numbers of protons and electrons, which are the same for isotopes. D is incorrect because isotopes have the same atomic number.

Answer

Number of electrons in a neutral atom

Answer

Number of neutrons

Answer

Atomic number

Answer

Number of protons

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