Answer:D
Explanation:
It was right o khan academy
Answer:
solid
Explanation:
they molecules are closely together
Answer:
100,000 times
Explanation:
Luminosity is the measure of brightness of a star. It is measured by examining the radiant energy emitted by the stars per second. Rigel's radius is about 80 times that of the Sun's radius. Therefore, its luminosity is about 100,000 times the sun’s luminosity.
Answer:
d. all of the above
Explanation:
a) Absolute dating technique is used to determine the age of rocks and fossil fuels, by the use of radioactive elements, such as, Carbon-14. The process involves the measurement of life of fossils through the remaining amount of radioactive element. It is possible by the knowledge of half life of radioactive element.
b) The radioactive isotope of Cobalt (Cobalt-60) is used to treat localized cancer. Other radioactive elements are also used to kill bacteria and treat cancer, such as, Iodine-131 is used to treat thyroid cancer
c) Radioactive elements are also used as tracers, such as Sodium-24, which is used as a tracer in blood. Other radioisotopes of Hydrogen, Carbon. Phosphorus and Sulfur, etc, are also used as tracers in different chemical reactions.
<u>Thus, all the given options are correct and the correct option is all of the above (d).</u>
