What is Spectroscopy?
What is Spectroscopy? Spectroscopy is the study of energy levels in atoms or molecules, using absorbed or emitted electromagnetic radiation. There are many categories of spectroscopy eg. Atomic and infrared spectroscopy, which have numerous uses and are essential in the world of science. When investigating spectroscopy four parameters have to be considered; spectral range, spectral bandwidth, spectral sampling and signal-to-noise ratio, as they describe the capability of a spectrometer. In the world of spectroscopy there are many employment and educational opportunities as the interest in spectroscopy and related products is increasing. However Spectroscopy is not a recent development, as it has been utilized for many years since Isaac Newton made the first advances in 1666. Spectroscopy is the study of light as a function of wavelength that has been emitted, reflected or scattered from a solid, liquid, or gas. Fundamentals of Spectroscopy Spectroscopy is the distribution of electromagnetic energy as a function of wavelength. Spectrum is basically white light dispersed by a prism to produce a rainbow of colours; the rainbow is the spectrum of sunlight refracted through raindrops. All objects with temperatures above absolute zero emit electromagnetic radiation by virtue of their warmth alone; this radiation is emitted at increasingly shorter wavelengths as temperature is
Hookes lab
PHYSICS LAB REPORT VERIFYING HOOKE'S LAW AIM: The aim of performing this experiment is to find out if the extension produced by a spring is directly proportional to the tension force applied to it and thus verifying Hooke's law. THEORY: Hooke's law is the relationship between the force exerted on the mass and its position x. Consider a object with mass m, that is on a frictionless surface and is attached to a spring with spring constant k. The force the spring exerts on the mass depends on how much the spring is stretched or compressed, and so this force is a function of the mass's position. The idea behind Hooke's Law is that any object that is initially displaced slightly from a stable equilibrium point will oscillate about its equilibrium position. It will, in general, experience a restoring force that depends on the displacement x from equilibrium. The extension or the strain will keep increasing as you increase the weight added as long as the spring doesn't remain stretched permanently. A point is reached where the spring can't stretch any more when more tension force is applied to it and snaps. This is defined as the 'elastic limit' of the spring. The force constant 'k' of a spring is the force needed to cause unit extension, i.e. 5cm. If a force 'F' produces extension 'e' then, k = F e HYPOTHESIS: As seen the Hooke's law states that the extension of a
road accidents
What can be done to reduce road accidents in Portugal? . Introduction Portugal has a high reputation of having many road accidents. It is currently 19th out of the 27 countries of the European Union in terms of fatality rate per citizen. This clearly puts Portugal in the negative side of the list. This is largely due to its recent history. In fact, one of the explanations for road accidents in Portugal is the fantastic growth in terms of highways and cars, and if that could be seen as a positive aspect related to the recent development of the country, the significant lack of education about this issue, on road safety and accident prevention, is something that we, urgently, need to solve. Portugal from 1990 to 2008 multiplied highways by 6 times making it the second country from Europe, being only behind Ireland (7). Finland, which was the third country in terms of highways increase, only multiplied by 3. The European Union has an average of 13 km of highway per 100.000 citizens, whilst Portugal has 17. According to the statistics in Portugal, from 1990 to 2010, the number of cars raised 103%. What did not happen in Portugal, which is essential, is driving education that enables people to respect the law, minimising the risks. Graph showing road deaths Source: Portugal: light blue line 2. Scientific Aspects 2.1 Cars Each year cars are getting better due to new
AIM OF EXPERIMENT: TO DETERMINE THE RATE OF REACTION OF HALOGENOALKANES
AIM OF EXPERIMENT: TO DETERMINE THE RATE OF REACTION OF HALOGENOALKANES EQUIPMENTS REQUIRED * Eye protection * Marking pens or labels * A test tube rack and 6 test tubes * Beaker ( 250cm3) * Bunsen burner, tripod stand * Measuring cylinder (10cm3) * Thermometer ( 0oC-100oC) * Stop clock * Source of laser light. * 1-bromobutane* * 1-chlorobutane # * 1-iodobutane* * Silver nitrate solution (0.1mol dm-3) * Ethanol# * Dropping pipettes : 1 for each bottle * Source of hot water * Harmful. Eye protection must be worn # Highly inflammable. Keep tubes and bottles away from naked flame. INTRODUCTION A halogenoalkane is a compound which has a carbon (C) - halogen(X) bond in its carbon chain. The C?+? X?-bond is polarised due to the difference in electro negativity between the carbon atom and the halogen atom. This induces the slightly positive charge on the carbon atom and the slightly negative charge on the halogen atom. The slightly positive charge on the carbon atom makes it open to nucleophilic attack. This results in the displacement of the halide ion. This experiment will compare the rate of hydrolysis of 1-chlorobutane, 1-bromobutane and 1-iodobutane where H2O acts as a nucleophile. METHOD: ) Fill a two-thirds of a beaker with water and insert a thermometer into the beaker 2) Heat water in a beaker till it reaches about 50oC 3) Put 1 cm3 of 0.1mol
To investigate how the resistance, R, of a length of wire, l, changes with diameter, D and determine the resistivity of the material the wire used.
Resistance of a Wire Aim To investigate how the resistance, R, of a length of wire, l, changes with diameter, D and determine the resistivity ? of the material the wire used. Introduction In this experiment, I am investigating the resistance, length and diameter to find the resistivity of a wire. Hence, we use the resistance formula to calculate this: R is the resistance of the conductor in Ohms (?) A is the cross sectional area in m2 l is the length of the wire in metres (m) ? is the resistivity of the material in Ohm metres (?m) Three external factors influence the resistance in a conductor. Thickness (cross-sectional area of the wire), length, and temperature all have some effect on the amount of resistance created in a wire. The fourth factor is the resistivity of the material we are using. The wires which are available for use are: Constantan (mm) Nichrome (mm) Cross sectional area (x 10-8m2) 2.d.p 0.19 2.80 0.23 4.10 0.28 0.28 6.10 0.31 0.31 7.50 0.37 0.37 0.70 0.40 2.50 0.45 0.45 5.90 0.56 24.60 0.71 39.50 0.90 63.50 .25 22.20 I found that it would be better to use the constantan wire because of the range of diameters, hence a wide range of cross sectional areas of wire are available. The temperature coefficients of the resistance for a constantan and nichrome wire are shown in the table below: Substance Temperature
In this coursework, I will be analyzing and proving that although metallic conductors are good conductors of electricity, they are affected by resistance.
PLANNING In this coursework, I will be analyzing and proving that although metallic conductors are good conductors of electricity, they are affected by resistance. But there are factors affecting the resistance of a conductor, and through my experiments I am going to prove that. CONDUCTORS We know that there are two types of conductors of electricity. Good conductors and bad conductors. Good conductors are that which conduct electricity the best. There are also some conductors, called semi-conductors, since they only half conduct the electricity that is passed through them. However, there are some materials, which resist the flow of electrons more that others do. These bad conductors are called insulators. Insulators are not needed to prove the factors affecting resistance, since they will be very invaluable, as they do not conduct electricity in the first place. When we talked about conductors conducting electricity, the very first question that comes up into our head is, 'How do conductors conduct is electricity?' In order to understand this, we have to learn about the structure of a metal, and to go deeper into it. Every piece of metal is made of electrons in the shells around the nucleus, which contains the protons and neutrons. Thus the atom is stable when it has the same number of electrons and protons. But when we examine a piece of metal closely, we can see that
Physics Research and Report - What is Antimatter?
Physics Research and Report What is Antimatter? Antimatter is matter that has the same gravitational properties as ordinary matter, but that has an opposite electric charge as well as opposite nuclear force charges. Matter is not common, it is very rare and can only be found in space, though now it can also be created right here on earth, but that is very expensive and takes many years to make. Though if successfully created, it can be a great source of energy. There are many implications with Antimatter, it is very unstable, and it reacts with almost anything, even air. Where does Antimatter come from? Some scientists say that Antimatter comes from neutron stars and black holes which are leaking out positrons into space. Antimatter has come from the same place as matter; the big bang, but they are both just different in that one way; there difference in charge. What will happen if Matter and Antimatter come into contact? If these two opposites come into contact, annihilation will take place, producing gamma rays. In other words it will be total destruction or complete obliteration. It produces pure energy, which can be dangerous if not contained properly, though if it is it can be useful in more ways than one. After annihilation, charge, momentum and energy are all conserved. Why is there more Matter than Antimatter? There is a substantial amount more Matter in
Find the critical angle and refractive index for plastic using a graphical treatment for my results.
Investigating Refraction Aim: Find the critical angle and refractive index for plastic using a graphical treatment for my results. Introduction: The Refractive Index is how the much a material bends the light. In this experiment I will be looking at the how much the angle of incidence gets refracted and I will multiply my results by sine. I will plot a graph from my results and, using a line of best fit, I will calculate the size of the angle of incidence in order for the refracted angle to be equal to 900 (critical angle). I will then calculate the refractive index by using Sine I and Sine R. I will be looking at light going from glass to air (from a dense medium to a lighter one). Theory: Incident ray: Ray of light before refraction. Angle of refraction (R): Angle between refracted ray and normal at point of incidence. Angle of incidence (I): Angle between incidence ray and normal at point of incidence. Point of incidence: Point at which incident ray meets boundary and becomes refracted ray. Critical angle: The particular angle of incidence of a ray hitting a less dense medium, which results in it being refracted at 900 to the normal. Normal: A line at right angles to boundary through chosen points. There are two main laws of refraction of light: 1. The refracted ray lies in the same plane as the incident ray and normal at the point of incidence. 2. (Snell's law). The
Black Hole
BLACK HOLE Group No. 6 A black hole is a theorized celestial body whose surface gravity is so strong that no light can escape from within it. It is one of the three postulated final stages of stellar evolution wherein a star's core cools and contracts and begins to collapse under the enormous weight of the outer layers. No black hole has ever been identified but scientists have described certain parts of the universe where they might exist. A black hole is a theorized celestial body whose surface gravity is so strong that no light can escape from within it. Although black holes have been of intense scientific interest only in the later 20th century, the concept goes back to the French mathematician Pierre Simon de Laplace. In a 1798 treatise Laplace agreed with Isaac Newton that light is composed of particles. He reasoned that if enough mass were added to a star like the sun, the gravitational force of the star would eventually become so great that its escape velocity would equal the velocity of light. At that point, light particles would not be able to leave the surface of the star, and it would blink out and become an invisible black star. More than a century later, Albert Einstein, in his special theory of relativity, maintained that nothing can move faster than light. This means that Laplace's black stars are also black holes, because if light cannot escape, all other
Investigation into the Physics of a Light Dependent Resistor.
Investigation into the Physics of a Light Dependent Resistor Introduction and Explanation of how an LDR functions In this essay, my aim is to examine the physics behind a Light dependent resistor by measuring the voltages across it when exposed to bulbs of various wattages. As with all experiments, it is necessary to make an initial prediction. I believe that the voltage across the LDR will increase if a higher wattage of bulb is used. However, we find ourselves asking the question, 'Why should the voltage change across this component just because the light intensity around it varies?' In order to answer this question we have to examine the physics behind an LDR. The LDR: 'Success in Electronics' (Tom Duncan 1983) provides this symbol as the representation of an LDR and tells us that this component, sometimes called a Photoresistor, varies its resistance according to light levels. The resistance of an LDR depends upon the amount of Charge Carriers inside the component. Charge carriers are particles which are capable of carrying charge (!) and are free to move across electron levels. According to Ohm's law, the resistance falls in the LDR as the current throughout the circuit increases. The reason for this increase in current is due to the greater number of charge carriers in the semi-conductor inside the resistor. In this case, the charge carriers are
