The number 0.00243

has how many significant digits

A sample of helium gas has a volume of 900. milliliters and a pressure of 2.50 atm at 298 K. What is the new pressure when the temperature is changed to 336 K and the volume is decreased to 450. milliliters?

What is matter that is composed of more than one substance

At a constant pressure, freezing occurs by A) absorbing energy B) releasing energy C) conducting energy D) circulating energy.

A 1000-kg car approaches an intersection traveling north at 20.0 m/s. A 1200-kg car approaches the same intersection traveling east at 22.0 m/s. The two cars collide at the intersection and lock together.

50g of ice at 0°C is mixed with 50g of water at 80°C, what will be the final temperature of a mixture in degrees C?

Which is a correct step in a scientific experiment involving acids and bases?

Objects can be accelerating and traveling at constant velocity at the same time. True or False

What kind of star gives rise to a type i supernova? a. white dwarf stars b. massive main sequence stars c. red giant stars?

Example of an object in motion

A proton and an alpha particle are momentarily at rest at a distance r from each other. They then begin to move apart. Find the speed of the proton by the time the distance between the proton and the alpha particle doubles.