2007-01-17 02:46:37 · 9 answers · asked by missy p 1 in Science & Mathematics ➔ Biology
It depends on what is in the water...
Eggs should NOT float in regular tap water! (Unless the egg has gone bad, in which case a gas is formed inside the egg which makes it rise to the top).
Egg shells may seem pretty solid, but they are in fact slightly porous. Old eggs float in fresh cold water because of a large air cell that forms as the egg cools after being laid. As the egg ages, air enters the egg and the air cell becomes larger and this acts as a buoyancy aid.
Generally, fresh eggs will lie on the bottom of the bowl of water. Eggs that tilt so that the large end is up are older, and eggs that float are rotten. The tilting is caused by air pockets in the eggs that increase in size over time as fluid evaporates through the porous shell and oxygen and gases filter in. The older an egg gets the more gas builds up inside it. More gas = more floating!
Eggs are denser than tap water. (Which means that an egg weighs more than an egg sized amout of water.)
However, if there is salt in the water, then the water becomes more dense than the good egg and the egg will float to the top.
Hope that helps! :)
2007-01-17 03:06:03 · answer #1 · answered by Matty A 3 · 2⤊ 0⤋
In between the shell and white of an egg is a membrane. At the big end of the egg, there is a small air pocket between the shell and membrane. Air can also pass through the shell. So over time, air passes through the shell and the air pocket grows. When an egg is first laid, the air pocket is small, so if you put ithat egg in water it won't float. After time, the air pocket will be big enough to cause the whole egg to float.
That's a good way to test the freshness of an egg. A fresh one won't float. After a few weeks the big end will point up. If the egg is really old, the whole egg will float.
2007-01-17 02:54:48 · answer #2 · answered by Anonymous · 0⤊ 0⤋
When an egg is old, it floats in water.
2007-01-17 02:53:18 · answer #3 · answered by lucky 2 · 0⤊ 0⤋
Because they are bad.
Good eggs sink.
Eggs that stand on end at the bottom of a glass of water should be used quickly.
Eggs that float should be disposed of.
2007-01-17 02:51:01 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Older eggs have a gas pocket and weigh less than the water they displace. Thus they float.
2007-01-17 02:53:45 · answer #5 · answered by Kes 7 · 0⤊ 0⤋
Eggs dont float in water unless they are boiled. maybe because of the built up pressure.
2007-01-17 02:51:41 · answer #6 · answered by Anonymous · 0⤊ 0⤋
because an egg has a lot of air in side it and the egg's material is less in density than water
2007-01-17 02:53:01 · answer #7 · answered by modalmasri 2 · 0⤊ 0⤋
because there is air inbetween the egg and the yolk!
2007-01-17 02:53:42 · answer #8 · answered by i♥photos 2 · 0⤊ 0⤋
um because thats how they are?
2007-01-17 02:54:57 · answer #9 · answered by shopgirl 2 · 0⤊ 1⤋