U-238
The number besides the U means its total molar mass. The molar mass of this element is 238
Molar mass= protons + neutrons
This means that 238= 146 + protons
Do 238 - 146
Answer is 92
D) Chlorine, Cl. Hope that helped
Answer: 4.5 x 10e-7
Explanation: 450 x 1e+9 = correct answer
Multiply amount of nanometers by 1e+9 to get the approximate result in meters.