Question

rubidium has an atomic number of 37 and a mass number of 85. how many protons, neutrons, and electrons does an ion of rubidium with a 1+ charge have? (1 point)

o 48 protons, 37 neutrons, and 36 electrons

o 37 protons, 48 neutrons, and 36 electrons

o 48 protons, 37 neutrons, and 38 electrons

o 37 protons, 48 neutrons, and 38 electrons

Explanation:

Step1: Determine number of protons

Atomic number = number of protons. Given atomic number of rubidium is 37, so number of protons = 37.

Step2: Calculate number of neutrons

Mass number = number of protons + number of neutrons. So number of neutrons = mass number - number of protons = 85 - 37 = 48.

Step3: Find number of electrons

A neutral atom has equal number of protons and electrons. An ion with a 1+ charge has lost 1 electron. So number of electrons = 37 - 1 = 36.

Answer:

37 protons, 48 neutrons, and 36 electrons (corresponding to the second option in the multiple - choice list)