If an element has 4 protons and 5 neutrons its mass number is

Thermal energy is created when a firefighter slides down a pole. Where does this energy come from?

The mass of an electron is 9.11 * 10-31 kg. What is the uncertainty in the position of an electron moving at 2.00 * 106 m/s with an uncertainty of Δv = 0.01 * 106 m/s?

In a science lab, when an acid is splashed on your skin what do you wash it with?

Is the formula for Mercurous Phosphate (or Mercury (I) Phosphate) (Hg2) 3 (PO4) 2 or Hg3PO4? I have looked it up on the Internet and I have seen it both ways.

Which of the following cell structures exhibits selective permeability between a cell and its external environment?

What water activities might be easier to do in Lake Assal's salty water? What activities could be more difficult?

The suffix "-megaly in the term gastromegaly means:

The harder you strike a drum, the greater the sound's A) medium B) volume C) frequency D) pitch

The equation X + Y 2Z has the rate law equation shown below. Which of the following statements best describes the relationship of X on the rate of the reaction? rate = k[X]2[Y] Changing X has no effect on the reaction rate.

What moves in or out of a substance during a change of state?