Helium is not found. That is 8 molecules of carbon, 10 Hydrogen, 4 nitrogen, and 2 Oxygen. I think...Hope this helps.
Wind speed because speed is how fast something moves
I'm not sure if this is your question but with NaCl (salt) and water it is homogeneous because when mixed, all the salt particles are even throughout and diffuse throughout the water.
Answer: put 2 in front of NaOH and 2 also in front of H2O
Explanation: 2NaOH + H2CO3 —> Na2CO3 + 2H2O
