To solve this problem, we need to consider two conditions about the metal:
1. The metal must not melt at temperatures up to [tex]\( 1000^\circ C \)[/tex].
2. The metal must have the best electrical conductivity among the provided options.
First, let's review the melting points of the metals from the table:
- Aluminum: [tex]\( 660^\circ C \)[/tex]
- Copper: [tex]\( 1085^\circ C \)[/tex]
- Zinc: [tex]\( 420^\circ C \)[/tex]
- Silver: [tex]\( 962^\circ C \)[/tex]
- Nickel: [tex]\( 1455^\circ C \)[/tex]
The metals that do not melt at [tex]\( 1000^\circ C \)[/tex] are:
- Copper (melting point [tex]\( 1085^\circ C \)[/tex])
- Nickel (melting point [tex]\( 1455^\circ C \)[/tex])
Next, we look at the electrical conductivity rankings to find which of these metals is the best conductor:
- Copper: Electrical Conductivity Rank 2
- Nickel: Electrical Conductivity Rank 5
Since the metal that doesn't melt at [tex]\( 1000^\circ C \)[/tex] and has the best electrical conductivity must have the lowest rank in the ranking system, we compare the ranks:
- Copper has a rank of 2.
- Nickel has a rank of 5.
Therefore, the metal the chemist has must be copper, as it doesn't melt at [tex]\( 1000^\circ C \)[/tex] and has the best electrical conductivity among the options.
So, the correct answer is:
B. copper
