Sinking or floating - the baby version

I have been musing for a few weeks about when to start trying some simple science-based activities with my smallest boy. He's currently ten months old and starting to use lots of gestures and show some understanding of words, although his spoken vocabulary is very limited (he has words for his parents and can tell you what a sheep says, but has no word for his brother...). 

I'm conscious that my eldest son had more opportunities to explore how things work at his own pace without someone else intervening.  However, he also had fewer people to watch and observe the impact they have on the world around them so their experiences as a baby are quite different.  Ideally I'd like to find a bit of quiet time for the little one to explore some activities in his own way, as well as playing alongside his brother when they are doing things together. 

My youngest boy has been enjoying some experiments with gravity in the form of dropping things off his high chair, and watching carefully where they go before wailing and pointing to get someone to pass them back.  Thankfully his big brother is now on board with his experiments and both attempts to explain gravity ("it's what makes everything fall towards the Earth") and quite often will retrieve the dropped objects for further experimentation.

During the big one's nap (he still has them some days), I decided to see what the small one made of sinking and floating. I took some food items and washed them (they were all to be used that afternoon so could be re-washed and cooked with no waste) and added a couple of metal spoons which would sink. I got a smaller clear plastic box than the bowl I use for the bigger one's experiments with sinking and floating to reduce mess, and filled it 3/4 full of warm water. We sat on a waterproof mat with some towels under the box of water and I gave him a tray of the foods/spoons to see what he would make of it. 

Objects for investigation - all safe to put in his mouth

He immediately picked up the lemon and investigated it with his hands before putting it in his mouth. I discouraged too much munching and he chose the lime next. I suggested putting the lime in the water, but he either didn't understand or didn't want to, so I demonstrated with the lemon, and he duly added the lime. He gave them a bit of a poke and splashed the water and I explained that the lemon and lime float at the top. 

He then went through the other food items, picking them up, having a look and either putting them down on the mat or in the water. I tried to emphasise what each one was called as he's not handled most of the foods before in their uncooked form. 

He left the spoons on the tray so I demonstrated putting one in the water and he did the other. I pointed to the bottom and said that they had sunk, and he promptly dipped his arm and sleeve in to try and reach them... Not sure why I hadn't put him in something with short sleeves first... He had some fun splashing, picking up the objects and dropping them back in and I talked to him about them whilst he was playing. We spent about 20 minutes with this activity before the amount of splashing got a bit too messy for my liking and I got rid of the water and let him play longer with the food and spoons after I'd put him in dry clothes.

Everything in the water, and a soggy sleeve

He definitely enjoyed it, but I haven't a clue what he actually learnt. He rarely gets a chance to quietly test whether things sink or float in the bath he shares with his brother so hopefully it at least gave him an opportunity to explore a bit at his own pace in addition to having a good look at some objects he hadn't seen before.