Identify the parts of the energy diagrams

Asample of radium-226 will decay 1/4 of its original amount after 3200years. what is the half-life of radium-226?

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?