[EmmyB (OP)]

Hi everyone,
my kids tried an experiment with two soda cans (355ml)  - one diet coke and one regular coke   - to see which one would sink and which one would float. And the cans seemed to behave as predicted.

However, when we tried the same experiment with smaller cans (222 ml), both diet and regular coke seem to float.

So why does smaller (222ml) can of regular coke floats when the larger regular coke sinks like a rock? The content seems to be same; density of the two cans should be about the same...

I have been searching online and have not found an explanation.
Different construction of the cans? More air in the smaller can? What am I missing?
Thanks!