Which of the following processes is an example of a physical change?

photosynthesis

rusting

sublimation

combustion

An object resting on a table weighs 100 n. with what force is the object pushing on the table? with what force is the table pushing on the object? explain how you got your answer.

Convert the temperature of dry ice, –77 ∞c, into degrees fahrenheit and kelvin.

Achemist who studies water samples did a demonstration of how to test for lead in water. she added a clear solution of potassium iodide to a clear solution of lead nitrate. then a yellow swirling solid formed in the liquid. what is most likely true about the yellow solid?