Final answer:
Steel loses approximately 50% of its strength at temperatures around 1100 degrees F due to the increase in atomic vibrations reducing the molecular forces in the metal.
Step-by-step explanation:
Steel loses about 50% of its ability to support mass when heated to temperatures near 1100 degrees Fahrenheit. At high temperatures, materials like steel weaken as the heat energy causes their atoms to vibrate more intensely and move around more freely, which reduces the molecular forces holding the material together. The weakening of steel at elevated temperatures is a critical factor in engineering and safety, particularly in the design of structures that may be exposed to fire or high thermal conditions.