I think it is C (answer at your own risk im not a professional)
Sodium Phosphide has a formula of Na3P . In order to bond ionically the charges must be equal and opposite. It will take one -3 phosphide ion to balance three +1 sodium ions forming a magnesium phosphide molecule of Na3P
All you have to do is explain the relationship between years and inches. The most rain was in 2004 with 10 inches and the least was in 1998 with 4 inches. In recent years there has been more rain than in the past. For the analysis just summarize that.
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.
