The choices for this problem are bismuth, Bi; platinum, Pt; selenium, Se; calcium, Ca and copper, Cu. I think the correct answer would be selenium. The melting point of bismuth is at a temperature of 544.4 Kelvin. At a temperature of 525 K, it would exist as solid. Platinum melts at 2041.1 K. At 525 K, platinum would be in solid form. Selenium has a melting point at 494 K so that at a temperature of 525 K, it would exist in its liquid state. Calcium has a melting point of 1112 K so it would exist as solid at 525 K. Copper has a melting point at 1358 K, so it would still exist as solid at a temperature of 525 K. Therefore, the answer would only be selenium.
Limestone and marble are the two rocks that are easily weathered by carbonic acid. Two kinds of weathering mostly affect the rocks. and they are physical weathering and chemical weathering. The above mentioned two rocks are highly affected by carbonic acid. The appeareance of these kind of rocks change their structure due to erosion very regularly. Caronation is the type of chemical weathering that affects the rocks limestone and marble. The carbonic acide is formed by the reaction of carbon dioxide in the air and water in the rivers. This carbonic acid results in weathering.
Speed in km/hr = 15 x 18
------------
5
= 54 km/hr.
Hope this helps!
The correct answer among the choices given is option B. Radioisotopes are isotopes that emit radiation because they have unstable nuclei. These are radioactive isotopes of an element. They are defined as atoms that contain an unstable combination of neutrons and protons.
The answer is nucleation because can turn liquids into solids.
