A scientist has a “mystery element” that she wants to identify by using its properties. These properties include its freezing point. She collected data about the element’s freezing point and displayed it on this graph.
The line shows a decreasing slope from 1650 °C until a little below 1500 °C from time 1 to 15 minutes. At a little below 1500 °C, the line flattens until 25 minutes. After 1500 °C, the slope decreases until 35 minutes.
Use the graph to determine the freezing point of the element. Which of these elements is the “mystery element”? The freezing point of each element is listed by its name.
A. silicon (1430⁰C)
B. nickel (1455⁰C)
C. cobalt (1495⁰C)
D. iron (1539⁰C)