Question

note: to answer some of the questions, it may help to reference a periodic table. examine the table. element number of protons number of neutrons number of electrons lead (pb) 82 125 82 radon (rn) 86 136 86 uranium (u) 92 146 92 francium (fr) 87 136 87 which element has the smallest atomic mass?

Explanation:

Step1: Recall atomic mass formula

Atomic mass = Number of protons + Number of neutrons

Step2: Calculate atomic mass of Lead

For Lead (Pb), atomic mass = 82 + 125 = 207

Step3: Calculate atomic mass of Radon

For Radon (Rn), atomic mass = 86+ 136 = 222

Step4: Calculate atomic mass of Uranium

For Uranium (U), atomic mass = 92 + 146 = 238

Step5: Calculate atomic mass of Francium

For Francium (Fr), atomic mass = 87+ 136 = 223

Answer:

Lead (Pb)