The official web site of the Nobel Prize explains that Marie Curie’s chemistry prize was partly for her discovery that the radioactivity of a substance is unaffected when it undergoes a chemical reaction. The discovery implied was that, Radioactivity involves Radioactivity involves only neutrons.
Explanation:
- The official web site of the Nobel Prize explains that Marie Curie’s chemistry prize was partly for her discovery that the radioactivity of a substance is unaffected when it undergoes a chemical reaction. The discovery implied was that, Radioactivity involves only neutrons.
- Marie Curie studied about the radiation of all compounds containing the known radioactive elements, including uranium and thorium, which she later discovered that they were radioactive.
- she discovered the following results,
- the exact measurement of the strength of the radiation from uranium;
- the intensity of the radiation was found to be proportional to the amount of uranium or thorium in the compound .
- the ability to emit radiation is not dependent on the arrangement of the atoms in a molecule;
- it must be linked to the interior of the atom itself which is a revolutionary discovery.
The answer is D) Velocity
Electromagnetic waves differ from mechanical waves in that they do not require a medium to propagate. this means that electromagnetic waves can travel not only trough air and solid materials, but also trough the vacuum of space.
Lower resistivity means higher conductivity: among these materials, the best conductor is silver, therefore it must be the material with lowest resistivity among those. We can also have a look at the value of resistivity of the different materials listed in the problem, to check our answer. The resistivities of the materials are the following:
Wood:
Salt water:
Silver:
Lead:
<span>We see that the material with lowest resistivity among those is silver, therefore the correct answer is silver.</span>
