When a fresh raw egg is gently placed in salt water of sufficiently high concentration, what will it do?

Introduction / Context:
This question illustrates an everyday application of the principle of density and buoyancy in liquids. Placing a fresh egg in plain water and then in salt water is a classic classroom demonstration used in school science experiments. The behaviour of the egg changes because the density of the surrounding liquid changes when salt is dissolved in water. Understanding why the egg floats in salt water helps reinforce the concept of relative density and Archimedes principle in a simple and memorable way.

Given Data / Assumptions:
– The egg mentioned is fresh and raw, not boiled or spoiled.
– The water is salt water with enough dissolved salt to significantly increase its density.
– The egg is placed gently into the solution, without external force pushing it down or stirring the water.
– We assume normal conditions where the density of a fresh egg is slightly higher than pure water but lower than sufficiently concentrated salt water.

Concept / Approach:
Whether an object floats or sinks in a liquid depends on relative density. If the density of the object is greater than the density of the liquid, the object sinks. If the object is less dense than the liquid, it floats. A fresh egg usually has a density slightly greater than that of pure water, so it normally sinks in plain water. When salt is dissolved in water, the solution becomes denser because dissolved salt adds mass without proportionally increasing volume. If enough salt is added, the density of the salt water becomes higher than the density of the egg. In that case, the egg experiences a buoyant force greater than its weight and floats near the surface of the liquid.

Step-by-Step Solution:
Step 1: Recall that a fresh egg typically sinks in plain water because its density is slightly greater than that of pure water. Step 2: Understand that dissolving salt in water increases the density of the water, especially when the salt concentration is high. Step 3: Visualise that in sufficiently dense salt water, the egg now has a lower density than the surrounding liquid. Step 4: Apply the rule of buoyancy that objects less dense than the liquid float, and conclude that the egg will float near the surface.

Verification / Alternative check:
You can verify this behaviour through a simple home or classroom experiment. Place a fresh egg in a glass of plain water and observe that it sinks. Then gradually add salt, stirring gently until it fully dissolves, and watch how the egg rises and eventually floats near the surface. This direct observation confirms the theoretical explanation about density and buoyant force. It is the same principle that allows people to float more easily in the highly salty water of seas like the Dead Sea compared with normal lakes.

Why Other Options Are Wrong:
It will sink and go to the bottom of the container: This happens in plain water but not in sufficiently dense salt water, so it is not correct for the conditions described.
It will sink but will not reach the bottom: In a typical demonstration, the egg either sinks completely in plain water or floats; the description of partial sinking is not the usual correct outcome for properly prepared salt water.
It will burst open due to pressure: The pressure difference in a small glass of salt water is not enough to cause a fresh egg to burst, so this is incorrect.

Common Pitfalls:
Some students forget that the density of the liquid can be changed by dissolving substances and wrongly assume that the egg must always sink, regardless of salt concentration. Others may confuse the case of a spoiled egg, which sometimes floats in plain water due to internal gas formation, with this controlled density experiment. To avoid such confusion, focus on the idea that adding salt increases the density of the water and use the rule that objects float when they are less dense than the surrounding fluid. This reasoning leads you directly to the correct outcome that the egg will float in concentrated salt water.

Final Answer:
A fresh egg placed in sufficiently concentrated salt water will float near the surface of the salt water.