What is the mass number of 207pb ? a: 289 b: 207 c: 125 d: 82

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

Consider the reaction: n2(g) + o2(g) ? 2no(g) kc = 0.10 at 2000oc starting with initial concentrations of 0.040 mol/l of n2 and 0.040 mol/l of o2, calculate the equilibrium concentration of no in mol/l how would this be done?

Which of the following has wavelength longer than the wavelength of viable light? a) x rays b) gamma rays c) radios waves d) ultraviolet waves