Uranium-238 alpha decays, emitting a helium-4 nucleus. What is the mass number of the product?

Which of these statements correctly applies the 2nd law of thermodynamics (the law of increasing disorder) to an air conditioner?

In the bottom, double-slit pattern shown above there are lots of small dark lines separating the band of red light into individual spots. The spots are not present in the top image. What causes these?

When the dynamite explodes, what happens to its mass?

Where on the periodic table can you find elements that typically will “take” two electrons in chemical reactions?

Professor Lawler borrows a spaceship and loads one of the lasers from a physics lab into it. She flies away in a straight line at constant speed going exactly half the speed of light.   As she flies off, she shines a beam of light from the laser back towards the science center and has one of her students measure how fast the light is going. What does the student find?

Which one of these forces is a result of an electromagnetic interaction?

You are given two clear solid crystals and told that only one of them is an ionic material. Both of them dissolve in water. How can you tell which one is the ionic material?

How does the momentum of the dynamite before the explosion compare to the total momentum of all of the pieces immediately after the explosion?

The next two questions deal with this situation: In one early experiment that helped determine the structure of matter, alpha particles were shot at a thin sheet of gold foil. The particles were detected on a screen that could be moved about the room.