The energy needed to ionize an atom of element x when it is in its most stable state is 500 kj mol21. however, if an atom of x is in its lowest excited state, only 120 kj mol21 is needed to ionize it. what is the wavelength of the radiation emitted when an atom of x undergoes a transition from the lowest excited state to the ground state

λ = 314.8 nm

Explanation:

E = hc/λ

E: energy

h: Planck constant = 6.62607015 × 10⁻³⁴

c: speed of light = 2.998 x 10⁸ m s⁻¹

λ: wavelength

Ground state:

E(gs) = 500 000 J

Lowest excited state:

E (les) = 120 000 J

Transition energy = E(gs) - E (les)

Transition energy = 380 000 J/mol

Transition energy = 380000 J/6.022x10²³ atoms

Transition energy = 6.31 x 10⁻¹⁹ J/atom

E = hc/λ

λ = hc/E

λ = (6.62607015 × 10⁻³⁴ x 2.998 x 10⁸ m s⁻¹) / 6.31 x 10⁻¹⁹ J

λ = 3.148 x 10⁻⁷ m

λ = 314.8 nm

it can be observed without changing the identity of the object.

it depends on what substance you're talking about as well as many other factors. in quantum mechanics, the observation of particles affects the observers ability to measure certain properties. for example: you can know the velocity of a particle, but you can't know it's position; or you can know it's position, but not it's velocity. it's like trying to find out where a grain of sand is by throwing other grains of sand at it. once you find out where it is, it's been moved. it's also like trying to find an answer to the question of whether or not a tree falling in a forest makes a sound if nobody is there to hear it. paradoxically, the only way to find out is to be there and hear it.