In this experiment, the dependent variable would be the same for every independent variable.
Although Rutherford's original hypothesis, based on J.J.
-Has a charge of 1- Definition- a positively charged subatomic particle that is found in the nucleus of an atom
-discovered by Ernest Rutherford
-amount of positive charge varies among elements
-each nucleus must contain at least one particle with positive charge
-each proton is assigned a charge of +1
-some nuclei contain more than 100 protons Proton Rutherford's Hypothesis In his model of the atom the mass and positive charge are evenly spread throughout an atom.
On the other hand, the neutron hypothesis gives an immediate and simple explanation of the experimental facts; it is consistent in itself and it throws new light on the problem of nuclear structure.
To be specific, let usconsider the gold atom, since the foil used by Rutherford was of gold, beateninto leaf about 400 atoms thick. The gold atom has a positive charge of 79 (balanced of course by that of the 79electrons in its normal state). Neglect the electrons—they'll be scattered away with negligible impacton the heavy alpha.
Based on this model, Rutherford hypothesized that the mass and charge at any location in the gold would be too small to change the path of an alpha particle.
The Committee concluded that concentrations of chloramphenicol in soil, as they were found under laboratory conditions in the presence of organic material, would suffice to explain occasional traces of chloramphenicol in tissues and products of free-ranging and/or scavenging livestock animals. With the LOD achieved in the 1950s, however, it was not possible to demonstrate the production of detectable amounts of chloramphenicol in soil. No further empirical data have been obtained since 1952. The possibility that chloramphenicol, produced naturally by soil microorganisms, could lead to the residues found in food-producing animals cannot be ruled out, but remains an unexplored hypothesis that is currently not supported by experimental data.
(The whole experiment was done in complete darkness.)
Instruments used to collect data:
Zinc sulfide screen (to catch the fluorescence of alpha particles bouncing off)
Alpha particle source
(Mainly) Gold foil
The diagram on the left shows the set up of the whole experiment, and the one on the right displays what is happening to the alpha particles on the atomic level.
Since nothing like his experiment had ever been done before, his hypothesis had to be theoretical.
This was the first time that this specific hypothesis was formulated.
Independent Variable- rate at which the alpha particles were shot out, and the location of the foil
Dependent Variable - number of electrons bounced back from the gold foil
This experiment did not have a control group.
In order to record the data, a zinc sulfide screen was placed behind the gold foil (though other foils were used as well) as a backdrop for the alpha (positive) particles to appear upon.
Thompson's Plum Pudding Model (left) and Cathode Ray Tube (below)
Rutherford hypothesized that every alpha particle would go directly through the foil, according to the plum pudding model.
His hypothesis was based on previous observation; J.J.
The experimental results were very difficult to explain on the hypothesis that the beryllium radiation was a quantum radiation, but followed immediately if it were supposed that the radiation consisted of particles of mass nearly equal to that of a proton and with no net charge, or neutrons.
Also, it motivated other scientists to study the atom more intricately.
Sue Youn Oh
Experiment Set Up
Setting of Experiment
Rutherford conducted his Gold Foil Experiment in 1911 at the University of Manchester, in the United Kingdom.
Ernest Rutherford was born at Spring Grove in Nelson, New Zealand on August 30, 1871, to James and Martha Rutherford.
A beam of was aimed at very thin gold foil and their passage through the foil detected. The scientists expected the alpha particles to pass straight through the foil, but something else also happened.
It is not within the scope of this monograph to describe the range of different production systems. An example of data that have been gathered in the western hemisphere can be found in tabular form in a publication of the National Academy of Sciences of the USA (National Academy of Sciences, 1994). However, under the hypothesis that soil ingestion could be the cause of chloramphenicol residues in tissues and edible products, extensive systems—as they still exist, for example, in south-east Asia, with free-ranging scavenging chickens receiving supplementary feeds—are of particular interest. Local breeds may play an important role, at least regionally (Nguyen Dang Vang & Le Viet Ly, 2000). Some of these breeds have small bodies and growth rates and feed conversion may vary largely (Tran Thi Mai Phuong et al., 2003). A limited amount of data from south-east Asia were available from published results of research projects. These results, which are not necessarily representative, are summarized in more detail in Appendix I. Selected data are presented in Figure 3. The study of Duong Duy Dong (2003) provided useful data for model calculations.