Question

investigation 4
physical properties of materials
the peak of mount everest is 8,848 meters above sea level, or about 5.5 miles. there is less oxygen in the air, and the temperature is always below freezing. mountain climbers depend on reliable equipment to survive in these conditions. choosing which materials to use when designing the equipment requires a great deal of thought. once you have viewed the investigative phenomenon video and completed the claim - evidence - reasoning exercise, answer these reflection questions.
1 ccc structure and function ice and water are made out of the same molecule, but they have very different properties. list two physical properties of both ice and water and describe how their structures result in those properties.
2 sep plan your investigation ice axes and carabiners are important tools used by mountaineers summiting snowy peaks. these objects need to be strong and reliable in cold temperatures. engineers have choices of materials to use in making these tools. plan an investigation that could provide the evidence needed to decide which material is best to use.

Explanation:

1. For ice, density is lower than water (ice floats) because its hydrogen - bonded structure creates a more open lattice. Its melting point is 0°C. Water is a liquid at room temperature, has a higher density due to closer - packed molecules, and has a high surface tension due to hydrogen bonding.
2. To plan an investigation for materials for ice axes and carabiners: Select candidate materials like steel alloys, titanium alloys, etc. Test their strength (using tensile testing machines) at cold temperatures (simulating mountain conditions, e.g., - 20°C to - 40°C). Also, test for brittleness by impact testing at those temperatures. Compare the results to determine the best material.

Answer:

1. Ice: Lower density (floats), melting point of 0°C due to open - lattice hydrogen - bonded structure. Water: Higher density, liquid at room temperature, high surface tension due to hydrogen bonding.
2. Select candidate materials. Test strength and brittleness at cold temperatures. Compare results to choose the best material.