Question

What causes the lines in the spectrum for elements? a continuous release of energy from the heated element a quantum absorption of energy as various electrons are excited to a higher energy level a quantum release of energy as electrons drop back to their ground state none of the above

Answer 1

A quantum release of energy as electrons drop back to their ground state.

Step-by-step explanation:

An atom of an element is said to be in its ground state when its electron is in the lowest energy orbit or shell of n=1.

However, when the electron absorbs energy it gets excited and jumps from this lower energy level to a higher energy level. Depending on the amount of energy absorbed, different energy orbits can be reached.

Also, in that excited state, the electron can lose energy and drop from orbit to orbit. This energy released is in discrete packets called quantum ( plural quanta ) and, using a spectrometer, can be observed as different lines, called the atomic line spectra, depending on the orbit the electron is dropping from.

A quantum of energy is given by:

E = hv = hc/

Where h = Planck's constant = 6.62 x 10-27 ergsec, c = velocity of light = 3 x 1010 cm/sec, v = frequency of the quantum energy emitted or absorbed in sec-1, = wavelength in cm.

There are 5 series of the atomic spectra in various regions of the electromagnetic spectrum for n = 1,2,3,4,5 respectively as, Lyman, Balmer, Paschen, Brackett, Pfund.

Answer 2

Answer:a quantum absorption of energy

Step-by-step explanation:

Bohr’s model explains the spectral lines .While the electron of the atom remains in the ground state, its energy is unchanged. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state and when the atom relaxes back to a lower energy state, it releases energy that is again equal to the difference in energy of the two orbits.