Three of the strongest lines in the He+ ion spectrum are observed at the following wavelengths: (1) 121.57 nm, (2) 164.12 nm, (3) 25.64 nm. Find the quantum numbers of the initial and final states for the transitions that give rise to these three lines. Use Equation 4, the wavelengths of lines that can originate from transitions involving any two of the four lowest levels. (1)--> (2)--> (3)-->

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

→

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.