How does the presence of a catalyst affect the activation energy of a reaction?

As a substance changes phase from solid to liquid to gas, the molecules become closer together.

Two charges that are 2 meters apart repel each other with a force of 2 x 10-5 newton. If the distance between the charges is decreased to 1 meter, the force of repulsion will be A) 1 x 10-5 N B) 4 x 10-5 N C) 8 x 10-5 N D) 5 x 10-6 N

Many people believe that a vacuum created inside a vacuum cleaner causes particles of dirt to be drawn in. actually, the dirt is pushed in. explain your answer.

How much space does 1pound of butter occupy if the density of butter is 0.94 grams/cm cubed

Why did one liter of have a greater mass than the other liter prepared by a different method

Which of the following is an example of applied research?

A Cadillac Escalade has a mass of 2,569.6 kg, if it accelerates at 4.65 m/s^2 what is the net force on the car?

If you are trying to balance a seesaw and you have a higher mass on the left, should the mass on the right be placed at a greater distance or lower distance to balance it? Why?

A car travels 300 km in the first 3 hours of a trip. Then it hits traffic and travels only 60 km during the last hour. What is the average speed of the car? a.) 180 km/h b.) 100 km/h c.) 90 km/h d.) 120 km/h

What is the purpose of using a wedge? A. separates objects B. keeps objects together C. allows you to exert force over a distance