El resultado de pasar a notación científica la cifra 2 000 000 000 · 10 -15

What happens in a global convection cell

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

An object moves from position +34m to the position -15m in 15 seconds. what is the total displacement? what is the total velocity?