We know that the equation for density is:

where D is the density, m is the mass in grams, and V is the volume.
Given two of the variables, we can then solve for density:

So therefore, we now know that the density of carbon dioxide gas is 0.00196g/mL.
Helium,it has an atomic mass of 4,which means total no. of protons and neutrons,so I think you meant 2 protons and an atomic mass of 4
Answer:
96 m/s.
Explanation:
Distance equals speed x time,
12 x 8, so the distance is 96 m/s.
By crushing the salt, you are performing a physical change because you aren't altering the chemical makeup of the salt, just the physical form. Hope this helps! :)