I think it's Sodium Sulfide, because Na2S contains one Sodium and two Sulfur. Plus Sulfide<span> is used to describe any of three types of chemical compounds that contain sulfur.</span>
<span>A fast way to separate the mixture would be to use a magnet. Iron is magnetic while copper is not. The second method would be to visually separate them since iron and copper distinctly different colors.</span>
The higher levels of gravity put on an object the more weight the object has. For example someone who weighs say 100 lbs would weigh more if higher amounts of gravity would be applied to them. And less if less gravity was applied. But larger objects will automatically have more gravity applied to them than something smaller due to the gravitational pull needing to pull harder to keep the object to the planet's surface. Hope this helps! :)
They all have something to do with heat