31 protons 31 electrons and 39 nutrons
The correct answer is B. The tendency of molecules to move toward areas of lower concentration is called diffusion. This happens when there is a concentration gradient. This is described by the Fick's laws of diffusion. Diffusion is the net movement of molecules from a higher concentration to lower concentration to achieve equilibrium.
Pressure is inversely related to temperature
Answer:
Only two elements are liquid at standard conditions for temperature and pressure: mercury and bromine. Four more elements have melting points slightly above room temperature: francium, caesium, gallium and rubidium.
Explanation:
