Holmgate Primary School And Nursery

Let your light shine

Respect, Responsibility, Resilience

Why is the sea salty?

Welcome to Japan's class page about our Summer 1 topic, why is the sea salty?


For this topic, we were very lucky to visit The Deep in Hull. The trip was absolutely awe-inspiring; we loved every minute of it!

As part of the day, we explored exciting exhibits including: the breath-taking coral reef at the Lagoon, the interesting animals in the slime exhibit, some of the biggest sharks in the Endless Ocean and creatures of the Amazon in the Flooded Forest.

We also took part in a slime time workshop, where we will be found out how animals use slime to survive, as well as making their own slime and testing its properties. This practical, hands-on workshop linked with our science topic, states of matter.

We were tired out by the end of the trip...

Is it possible to make a potato float?

We investigated if it is possible to make a potato float in salty water. If so, how much salt does it take to make a potato float? As part of our investigation, we looked at how to make our experiment a fair test by understanding what needs to be kept the same and what we will change (our variable). We then made predictions before completing the experiment. We found out that it takes roughly 7 dessertspoons of salt to make a potato float. We discovered that the reason this happens is because salt makes water thicker (more dense).

We then conducted a second experiment, where each group could decide themselves what variable they wanted. One group wanted to see if a carrot would require more or less salt than to float than a potato. The other groups investigated whether cola or lemonade could affect the amount of salt needed to make a potato float. The results were surprising, but we used our scientific knowledge to think about why our results came out as they did.