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Date:
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Homework: What Would Rutherford do?
Directions: Fill in the blanks in the story below using information you learned today. Words may be used more than
once or not at all.
Many years ago, before the days of cars and television, scientists were still trying to figure out the
structure of an atom. One of the big names in chemistry was Ernest Rutherford, a New Zealand-born
physicist and chemist. In 1906, he and a colleague named Thomas Royds proved that alpha radiation was
made up of helium ions. However, his most famous work was the gold foil experiment. Previous to this
experiment, the model of the atom was based on J.J. Thomson’s theory of negatively charged particles in a
positive “pudding”. Rutherford’s experiment involved firing particles with the symbol 42𝛼, or
_____________________________, at a very thin sheet of gold foil. Rutherford’s hypothesis was that these
particles would pass straight through the foil with little deflection. However, the particles, which had a
_______________________ charge and _________________ penetrating power, moved in three different
ways. These are now referred to the three conclusions of Rutherford’s experiment. The first conclusion was
that most of the particles passed through without deflection, signaling that the atom was mostly
____________________________-. The second conclusion was that the particles that hit the center
immediately bounced back, signaling that there was a very dense concentration of mass in the center. The
third and final conclusion was that the particles which passed near the center were immediately deflected
outwards. Thus, Rutherford concluded that at the center of the atom must lie a dense, concentrated positive
charge. We now know this to be the nucleus.
Unfortunately, for all his accomplishments, not all ended well for Rutherford. In the late 1930’s, he
began to feel ill. While it was not clear at the time what was ailing him, it was eventually found to be a
hernia. Eager to get better and continue his prolific scientific career, Rutherford elected to have surgery.
Although the surgery was successful and cleared most of the problems from the hernia, all did not end well.
Following surgery, multiple complications occurred, and Rutherford died at the age of 66.
With developments in modern medicine, perhaps Rutherford’s life could have been saved. Currently,
beta particles, with the symbol____________, are used to treat various health conditions, including eye and
bone cancer. It is possible that these particles, with _______________ penetrating power and a
________________ charge, could have helped Rutherford. However, beta particles also have another use in
medicine. Several _____________, or variations of an element with different numbers of neutrons, are used
as radiotracers. One of the most common is a 90 amu isotope of the element with an atomic number of 38,
__________________. This isotope with a notation of _____________________ (Use the format: Elementmass number) is generally the source of the beta particles for medical applications, although it also has other
uses. In fact, ________________________________, which have a negative charge, are also used in quality
control to test the thickness of an item. This is because if the item is too thin, a beta particle will pass
through it, while a(n) _________________________________ will not. On the other hand, if the item is too
thick, beta particles will not pass through, while __________________________________ will. This
phenomenon is due to the level of penetrating power of each of the types of nuclear radiation.
_______________________________ have the lowest penetrating power, ______________________ have
medium penetrating power, and _________________________ have the highest penetrating power.
Aside from ____________________________, which are the heaviest form of nuclear radiation, and
________________________ which have a symbol of −10𝛽, there is one more form of nuclear radiation. This
form, known as __________________________________, has the highest penetrating power. Furthermore,
it is the only form of nuclear radiation that has neither a __________________ nor a
___________________. This form of nuclear radiation has many uses, including sterilizing medical
equipment, and killing viruses and bacteria. Additionally, like beta particles, _______________________,
with a symbol of 00𝛾 , are used in medical applications. One of the medical applications is in nuclear imaging.
PET scans, a technique used to produce a 3D picture of the functional processes in the body, uses a
radiolabeled sugar that eventually is converted into pairs of gamma rays that can then localize cancer. The
most common radioisotope for these medical applications is an isotope of a transition metal in group 7B, an
atomic number of 43, and a mass number of 99. This isotope with a notation of _____________________
(Use the format: Element-mass number) has been beneficial in tracing conditions and making sure that the
patient is safe. Additionally, gamma rays are often used to treat some types of cancer. In fact, a specific
type of surgery, called gamma-knife surgery, involved shooting multiple concentrated beams of gamma rays
on the cancerous growth to kill the cancerous cells.
Despite developments in modern medicine, they unfortunately were not present at the time of
Rutherford’s unfortunate death in 1937. Nevertheless, Rutherford is remembered as one of the five most
important scientists in chemistry, particularly for his contribution to our current understanding of the atom.
As we continue to learn more in the field of chemistry and of the atom itself, it is clear that Rutherford’s
legacy lives on. Thus, whenever confronted with a problem or a question, we can ask ourselves:
“What would Rutherford do?”