Today we used some basic household materials to show how the density of a liquid can be increased by adding in another substance. In this case, we used water, salt, and eggs.
In the first demonstration, we had one container of fresh water and one container of salt water. We cracked open the an egg in each and observed that it will sink to the bottom of freshwater, but will float on top of salt water. The students had some great questions- does it matter if the yolk and albumen are separated? What happens if we stir both containers? What happens if we break the yolk?
In the second, we wanted to find out how much salt it would take to make an egg float (still in the shell). We started with fresh water and stirred in small amounts of salt until it floated on top. We used 300ml of water, and it took approximately 40g of salt.
We had some great conversations about the egg floating due to the water having more "stuff" (matter/particles) in it to support the egg.
In the first demonstration, we had one container of fresh water and one container of salt water. We cracked open the an egg in each and observed that it will sink to the bottom of freshwater, but will float on top of salt water. The students had some great questions- does it matter if the yolk and albumen are separated? What happens if we stir both containers? What happens if we break the yolk?
In the second, we wanted to find out how much salt it would take to make an egg float (still in the shell). We started with fresh water and stirred in small amounts of salt until it floated on top. We used 300ml of water, and it took approximately 40g of salt.
We had some great conversations about the egg floating due to the water having more "stuff" (matter/particles) in it to support the egg.