Answer:
a)
Explanation:
The temperature of 525 K, so to identify which is the state of a substance, we need to now the melting and the boiling point of it, which can be found in thermodynamic tables. To be liquid, the melting point must be less than 525 K (so the substance is not a solid anymore), and the boiling point must be higher than 525 K (so the substance doesn't go to gas).
Substance Melting point at 1 atm (K) Boiling point at 1 atm(K)
Bi 544.7 1837
Pt 2041.4 4098
Se 494 958
Ca 1115 1757
Cu 1357.77 2835
Thus, when pressure increase, the melting point decrease, so, if the pressure is little higher than 1 atm, then bismuth can be found as a liquid at 525 K. The others would need a higher pressure to be liquid at 525 K.
