1. Is a sample containing molecules of ammonia gas considered a pure substance? **Explain your answer. ** 2. Based on the model, what is the chemical formula for a molecule of ammonia gas?

An object is dropped from a tower, 400 ft above the ground. the object's height above ground t seconds after the fall is s(t)equals400 minus 16 t squared. determine the velocity and acceleration of the object the moment it reaches the ground. the velocity of the object the moment it reaches the ground is nothing ft/s.

What is the average speed of a car that travels 40mph for 1 hour and 60 mph in another hour will mark brainliest

Selma made a diagram to compare convection and radiation. which label belongs in the area marked x? must involve temperature differences between substances or objects only occurs when molecules are in direct contact involves the movement of fluids based on density differences can occur where there is little or no matter