<span>Molten material found in the bottom of seafloors indicated underwater eruptions that formed new areas of the seafloor was presented as evidence for seafloor spreading. Due to earths magnetic polarity and its tendency to switch, iron present on the sea floor contained a magnetic record of sea floor expansion progress. Finally, drilling samples obtained in the seafloor indicated the deeper samples of were significantly older than the shallower samples that were brought up.</span>
<h2>Answer is option "b"</h2>
Explanation:
- Non-ionizing radiation is radiation that has a lower frequency, or longer wavelength, in the EMR spectrum. These frequencies range from that of power lines, radios, and cell phones, up to visible light. Non-ionizing radiation is not powerful enough to break the chemical bonds in molecules. In general, it is not harmful to human health as radiation per se, but could be harmful in terms of the transfer of heat energy. An example of an emitter of non-ionizing radiation is a microwave oven.
- Non-ionizing radiation is less harmful because the rays carry much less energy. Radio waves, light, and even heat are examples of non-ionizing radiation. For the most part, these kinds of radiation do not cause any damage. However, ultraviolet light is a kind of non-ionizing radiation that can be harmful - it can cause mutations in DNA
- Non-ionizing radiation is limited to the lower energy range electromagnetic radiation, which is more commonly known as light. However, the light we can see with our eyes, visible light, is only a small section of the electromagnetic radiation spectrum as seen here
- Hence the right answer is option "b"