Inorganic topic 1 - electromagnetic radiation and atomic spectra Flashcards
Define radiation
The emission of energy wave or as moving subatomic particles, especially high energy particles that cause ionisation
What is the electromagnetic spectrum
The different types of radiation arranged in order of wavelengths
What is the wave model
electromagnetic radiation is the flow of energy at the speed of light through space or a medium as waves
What is the particle model
electromagnetic radiation is the flow of particles called photons through space.
what does the different types of radiation in the particle model correspond to
different amounts of energy per photon
What does the EM (electromagnetic) spectrum show a range of interactions with
particles in atoms, molecules and larger objects
the way matter interacts with EM radiation gives information about what? what are these interactions dependent on?
gives information about the structure of atoms, they are dependent on the frequency of radiation
what is wavelength
the distance between two adjacent wave crests and troughs (top of 1 wave to another)
What symbol and units are used for wavelength
symbol - lambda λ
units - metres (m) or nanometres (1nm = 10-9m)
what is frequency
the number of waves passing a fixed point in one unit of time, usually seconds
what symbol and units are used for frequency
symbol - f or v
units - reciprocal of time (s-1) or hertz (Hz)
As wavelength increases, what happens to frequency?
descreases
what is the equation for wavelength
c = fλ
What is the wave number
the reciprocal of the wavelength, given the symbol ‘nu bar’
what does the wave number define
the number of waves in a unit of length (usually 1m or 1cm)
what type of frequency waves carry the most energy
(2 examples)
high frequency waves eg gamma and x-rays
x-rays and gamma rays have energy equivalent to or above what?
an atoms ionisation energy
what does the x-rays and gamma rays energy equivalent to or above an atoms ionisation energy lead to
the ionisation of atoms - they lose elections. this is ionising radiation and is potentially harmful
what is the range of wavelengths of the visible spectrum?
380-750nm
what cells are the wavelengths detected by in the eye
rod (light detecting) and cone (colour detecting)
what happens when electromagnetic radiation interacts with matter?
energy is transferred from the radiation source to the receiving matter
what type of behavior does radiation show, whats the 3 examples of this
wave-like behavior - diffraction patterns, transmission and wavelengths
how does radiation show particle behavior
when it interacts with matter - as units of transferrable energy
define photons
a stream of particles with wave-like properties. they are massless, chargless, pockets of energy - with a specific wavelength that travel at the speed of light
what happens when photons are absorbed by a substance
the electron in the substance gain energy
what happens when photons are emitted by a substance
the electron in the substance loses energy
As energy increases…
frequency increases, and wavelength decreases
as energy decreases…
frequency decreases, and wavelength increases
what can photons in high frequency radiation do?
they an transfer greater amounts of energy than photons in low frequency radiation
the energy levels that contains electrons in atoms are quantised. what is quantised?
the energy levels have discreet energy values (specific)
what is each energy level in an atom allocated
a quantum number (n) - the first being n = 1 and so on up to n = 7
what is ground state
the lowest possible energy an atom can be
