What is required for an electron to move between energy levels?

What is i fracture in the crust called when land move up, down or sideways

What is the percentage composition of carbon in the compound ch4

He table below gives the atomic mass and relative abundance values for the three isotopes of element m. relative abundance (%) atomic mass (amu) 78.99 23.9850 10.00 24.9858 11.01 25.9826 what is the average atomic mass (in amu) of element m? 2.86 5.36 24.30 24.98