The mass of the most common isotope of an element is known based on an element's

A. mass number

B. average atomic mass

C. atomic number

B. number of electrons

A 1200 kg car is moving at 5.0 m/s east. it strikes an 1800 kg car at rest. the cars have an elastic collision and move in the east or west direction. the velocity of the 1200 kg car after the collision is:

What will happen to the springy iron strip if the current stops

Why did scientists agree to use one system of measurement

Which of the following statements about Boyle's law are correct? The temperature and pressure must remain constant for the law to apply. The temperature and the number of molecules must remain constant for the law to apply.

Find δerxn for the combustion of naphthalene. the heat capacity of the calorimeter, determined in separate experiment, is 5.11kj/∘ c.

Which of the following is an example of potential rather than kinetic energy? a. water rushing over Niagara Falls b. a molecule of glucose c. a crawling beetle foraging for food d. light flashes emitted by a firefly

If a force of 15 newtons [N] is applied to a surface and the pressure is measured as 4,000 pascals [Pa], what is the area of the surface in units of square milimeters [mm2 ]?

An engineer has the task of producing an aluminum alloy with a density of 3.0 grams per cubic centimeter. She comes up with the perfect alloy and saves a sample of it. Which mass and volume measurements correspond to this sample? 7 g and 2.

What must be your car's average speed in order to travel 235km in 3.25 hours?

At a certain location, the horizontal component of the earth's magnetic field is 2.5 * 10-5 T, due north. A proton moves eastward with just the right speed for the magnetic force on it to balance its weight. Find the speed of the proton.