I think you should try this experiment for your self. My son had to do a science fair project on school titled Do Eggs Float. He had to do a raw egg vs a boiled egg submerged in tap water, purified water and salt water. The raw egg only floated in the salt water and the boiled egg floated in all three types of water. Its the density in the water and the extra air pockets in the boiled egg that causes it to float. I urge you to do the experiment and see, its pretty neat. You use 6 tablespoons of table salt to 1 and a half cups of purified water.
It depends on what you're trying to float them in! They will both sink in fresh water (regular tap water), but if you add enough salt to the water (to make salt water), they will both float. :) This is because salt water is denser than an egg (cooked or raw), but an egg is denser that fresh water!
Hard boiled eggs float. Thats how you can tell they are finished cooking. If a raw egg will floats in water it is spoiled. Excessive bacteria inside the raw egg creates oxygen and causes it to float.
Nope it is the same as if floating in regular water. The egg is still more dense.