Something that affects the rate of a chemical reaction without being changed itself

What is the partial pressure of the third gas, helium?

Neptune's Triton is being pulled closer and closer to the planet as it orbits. What will likely be a result of this gravitational force in the future?

How does the Humidity of air affect the type of snow that falls?

What is a material that contains three elements joined in a fixed proportion

In bohr's atomic theory when electron moves from one energy level to another energy level closer to the nucleus: A. Energy is emitted B. Energy is absorbed C. No change in energy occurs D. Light is emitted E. More than one of these might occur

A laboratory experiment requires 250 millimeters of water for boiling. It also requires 100 millimeters of water for a cooling process.

Which set of procedures and observations indicates a chemical change? A) Ethanol is added to an empty beaker and the ethanol eventually disappears. B) A solid is gently heated in a crucible and the solid slowly turns to liquid.

If 100 grams citric acid react with 100 g baking soda how many grams of carbon dioxide?

What state of matter undergoes changes in volume most easily? a. solidb. liquidc. gasd. frozen

What was the result of the atomic theory?