Inorganic and Physical Chemistry
Give 3 examples of electromagnetic radiation
X-rays, TV and RF signals
What does wave length vary between?
10 to the power of -14 and 10 to the power of 14
What is the speed of all electromagnetic waves?
3X10 to the power of 8
What is frequency?
The number of complete waves passing a point per unit time
What is wave number?
The reciprocal of wavelength
What does reciprocal mean?
One divided by the number you have
What colours are in the visible spectrum of light?
Violet, blue, green, yellow, orange and red
What does the symbol C refer to?
The speed of light
What does the symbol lamda refer to?
Wavelength
What does the symbol v refer to?
The frequency
What are the small packets that energy is transferred in?
Quanta
Explain wave-particle duality
Sometimes energy can act as a wave or can act as a particle. The particles of energy are known as photons
What is the name of the constant L?
Avagadro’s constant
What happens if sufficient electrical energy is passed into a tube of gas at low pressure?
The gas atoms become excited and emit electromagnetic radiation (light)
What happens when light passes through a glass prism?
A spectrum is obtained
What are line spectrums obtained when light passes through a glass prism called?
Emission spectra
How is a line spectrum produced?
By the fine beam of light being passed through a diffraction grating
What is the relationship between Avagadro’s number and the mole?
Avogadro’s number is a proportion that relates molar mass on an atomic scale to physical mass on a human scale
What is used instead of a prism in modern spectrometers?
Diffraction grating
What does an emmision spectrum show?
Lines of precise frequencies
What do the precise frequencies shown in an emission spectrum correspond to?
The precise emissions of energy
What is the equation used to find the exact size of energy changes in an emmision spectrum?
E=Lhv
What are atoms said to be when they absorb energy?
Excited
How do emission spectrums arise?
From the movement of electrons from higher to lower energy levels when an excited atom returns to its ground state
What does the frequency of the line in the emission spectrum correspond to?
Difference in energy between 2 different electronic energy levels