1.3.1 and 1.3.2 - Emission Spectra Flashcards
(22 cards)
When do atoms of different elements give out light of a distinctive colour?
when an electric discharge is passed through a vapour of the element
How can metals be identified similarily to the distinctive colours of light of different elements?
When their compounds are heated in a bunsen burner, a distinctive colour of flame produced
How is electromagnetic radiation emitted?
in different forms of different energies
What is similar about all electromagentic waves?
they travel at the speed of light (c)
How are electromagnetic waves distinguished?
by their different wavelengths
What makes colours different?
they each have different wavelengths
What is frequency?
the number of waves that pass a particular point in one second
What is white light?
a mixture of different wavelenghths/colours
What happens when electromagnetic radiation is passed through a collection of atoms?
some of the radiation is absorbed and used to excite the atoms from a lower energy level to a higher one
When do gases produce an emission line spectrum?
when they are heated to a high temperature or if a high voltage is applied
What is ground state?
the lowest possible energy level
What form of energy is emitted when an electron falls into a lower energy level?
electromagnetic radiation
What is a photon?
a packet of energy
When is a photon released?
at every electron transition to a lower energy level
What is the energy of the photon of light emitted equal to?
the energy change of the electron in the atom
Why is the energy of an atom said to be quantized?
because there is no energy between energy levels, so it is discrete (non-continuous)
Why is the line spectrum evidence for quantization?
because otherwise, the emission spectrum would be continuous
What kind of information do line spectra give?
information about electron configurations of different atoms as each element has a different line spectra
What do transitions of electrons to the first energy level (n=1) correspond to?
the highest energy change, this is in the untraviolet region of the spectrum
What do transitions of electrons to the third or higher energy levels correspond to?
lower energy changes, this is when infrared radiation is produced
What does it mean when an electron is at the highest energy (n=infinity)?
it is no longer in the atom and the atom has been ionized
What is the ionization energy?
the energy needed to remove an electron from the ground state of one mole of gaseous atoms, ions or molecules
