Color of Gold Practical Report
Nanotechnology | Colour of Gold | Practical Investigation Report | |
Introduction
Gold is a precious metal which has been used for years and when we think of gold we think of shining bars in a bank vault, coins or beautiful jewellery. When we think of gold it’s usually a shining yellow gold however can come in many colours. The colour of gold can range from red through the visible spectrum to purple and violet.
Aim
The whole point of this experiment was to create gold that wasn’t the colour gold. The aim was to find out how a variable amount of sodium citrate would change the colour of a gold solution. Meaning the hypothesis was: if more sodium citrate is added the nano particle size will increase and the colour of the gold solution will move towards the red end of the spectrum.
Theory
Nanoparticles are different colours because of the way the electron waves at the edge of the matter interact with the light spectrum. A change in particle size will change the colour of the matter; another factor which affects the colour is the shape the particles broke into when the nano particles were made.
The way humans see colour is from the visible light spectrum hitting an object, some of the light goes through some is absorbed and some bounces back. We see the colour of the visible light spectrum which bounces back. Light is absorbed when it hits an electron which has the correct band gap to become excited by the energy level of that specific light photon. When the energy level in the photon drops so that none of the band gaps cover it then it can either pass through and get absorbed by electrons further into the matter or it will be reflected back.
Procedure
Materials
* Electric hotplate * Pipette / micro pipette * Conical Flask * Laser beam * Magnetic stirrer * Sodium Citrate * Stirring rod | * Wooden Peg * 10 ml Measuring cylinder * Curvette * Spectrophotometer * Gold Solution (HAuCl4) * Heat proof mat |
Introduction
Gold is a precious metal which has been used for years and when we think of gold we think of shining bars in a bank vault, coins or beautiful jewellery. When we think of gold it’s usually a shining yellow gold however can come in many colours. The colour of gold can range from red through the visible spectrum to purple and violet.
Aim
The whole point of this experiment was to create gold that wasn’t the colour gold. The aim was to find out how a variable amount of sodium citrate would change the colour of a gold solution. Meaning the hypothesis was: if more sodium citrate is added the nano particle size will increase and the colour of the gold solution will move towards the red end of the spectrum.
Theory
Nanoparticles are different colours because of the way the electron waves at the edge of the matter interact with the light spectrum. A change in particle size will change the colour of the matter; another factor which affects the colour is the shape the particles broke into when the nano particles were made.
The way humans see colour is from the visible light spectrum hitting an object, some of the light goes through some is absorbed and some bounces back. We see the colour of the visible light spectrum which bounces back. Light is absorbed when it hits an electron which has the correct band gap to become excited by the energy level of that specific light photon. When the energy level in the photon drops so that none of the band gaps cover it then it can either pass through and get absorbed by electrons further into the matter or it will be reflected back.
Procedure
Materials
* Electric hotplate * Pipette / micro pipette * Conical Flask * Laser beam * Magnetic stirrer * Sodium Citrate * Stirring rod | * Wooden Peg * 10 ml Measuring cylinder * Curvette * Spectrophotometer * Gold Solution (HAuCl4) * Heat proof mat |
Bibliography: Gold. (n.d.). Retrieved 03 14, 2012, from Causes of Colour: http://www.webexhibits.org/causesofcolor/9.html unknown. (2009, 07 1). Gold Particles 101. Retrieved 3 14, 2012, from Introduction to Nanotechnology: http://nanogloss.com/nanoparticles/gold-nanoparticles-101/#axzz1p2g6qkSO