How many helium atoms are in a helium blimp containing 498 kg of helium?

Which statement justifies that phosphine (ph3) is a polar molecule?

Identify two types of chemical bonding in the source of dietary potassium

If a simple machine aduces the strength of a force, what must be increased? the speed of the input force the work the simple machine performs the size of the simple machine the distance over which the force is applied