Have a go at some of these fun investigations! Share your results on the blog.
Equipment: 3 eggs, 3 clear beakers/glasses, water, salt.
How to: pour water into each glass; into one of the glasses, add 8 tbsp of salt and mix well; into another glass, add 4 tbsp of salt and mix well; add no salt to the third glass; place an egg into each glass and see whether it floats.
Taking it further: can you make an egg float halfway up the glass? What is the salt doing to the density of the water? What if you substituted the salt for sugar, does it work in the same way?
Make a Bouncy Egg
Equipment: 1 egg, white vinegar, jar.
How to: put the egg into the jar; pour in enough white vinegar to completely cover the egg; leave the egg for 24 hours (you will see bubbles form on the side of the egg and rising to the surface; this is a chemical inside the vinegar slowly dissolving a chemical inside the shell of the egg); take the egg out of the vinegar; carefully rub off any excess bits of shell; try out your bouncy egg – how high can you bounce it before it breaks?
Taking it further: do different types of vinegar work in the same way? What about different sizes of eggs?
Equipment: 2 toilet roll holders, 2 eggs, 2 glasses of water, shallow cake tin.
How to: place the tin over the center top of one of glasses of water; place the toilet roll tube in the middle of the tin; place one of the eggs on top of the tube; give the side of the tin a firm tap to push it off the top of the glass. The egg should drop straight into the glass of water due to the first law of motion.
Taking it further: try the same experiment with both eggs and both cardboard tubes. Does the same thing happen? What is the first law of motion?