Yes that’s correct it is B
Gamma radiation have the most penetrating power. It can penetrate through human body, aluminum and other metals. It can be stopped by lead. Hence, the radioactive waste are stored in lead container for safety purposes. The beta ray has more penetrating power than the alpha but less than gamma. The beta radiations can be stopped by aluminum. The alpha radiations have least penetrating power and it can be stopped by human hands.
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.
N2H4
<span>Each nitrogen weighs 14.01 and each H weighs 1.01. !4.01+14.01+1.01+1.01 = 32.06 (roughly) </span>