According to the weighing method: f float =G-F pull = 0.6n-0.1n = 0.5n;

(2) As shown in Figures B and C, the volumes of eggs soaked in the two liquids are different, so it is impossible to compare the relationship between buoyancy and liquid density, and it is necessary to control the volume of liquid that eggs are displaced to be the same;

(3) As can be seen from the picture, eggs submerged in water look bigger than those in the air; The part of the egg immersed in salt water looks bigger than that in the air;

So the answer is:

( 1)0.5;

(2) no; In the experiment, the amount of liquid discharged by eggs is not controlled at the same amount;

(3) The egg looks bigger in water than in air (or the part of the egg immersed in salt water looks bigger than in air).