Earth's crust is primarily composed of several elements, among which silicon, aluminum, and iron are common. The crust is made up of several large pieces of solid rock called tectonic plates. These tectonic plates include the Pacific Plate (PAC), North American Plate (NAS), Indian Plate (IND), and Australian Plate (AUS). Geologist Maria Silva led a team that calculated average melting points for these elements in the crust from different tectonic plates. Her team discovered that each of these elements exhibits slightly different melting points depending on whether it is found in the PAC, NAS, IDN, or AUS. For example, whereas the average melting point for aluminum from the North American Plate (NAS) is 663.5°C, the average point for aluminum from the Pacific Plate (PAC) is 660.3°C.Choice A is the best answer. According to the text, geologist Maria Silva and her team measured the average melting points of different elements found in various tectonic plates. They discovered that there are small differences in the melting points depending on the source. Choice A is the best answer as it compares the small difference in average melting point for aluminum between the North American plate (NAS) and the Pacific Plate (PAC).
Choices B and C: These choices compare the average melting points of different elements.
Choice D: This answer choice does not accurately reflect data on the table.
✨ Expert's Tip ✨
Identify the team's discovery in the text and find the answer that reflects the example from the chart.
