Wednesday, April 15, 2015

Weird Science Wednesday: Rain in a Jar

Since April showers do bring May flowers, I thought it'd be fun today to learn a little about why it rains. I've read about the rain in a jar experiment several times before and it seemed easy enough so we gave it a try!


  • Large glass jar (a large mason jar or tomato sauce jar would work well)
  • Water
  • Heat-resistant plate
  • Ice cubes
1. Boil enough water to fill your jar up about 2". For us, this came out to about a cup of water. We heated the water in a glass measuring cup in the microwave until it was very hot and boiling. Little C absolutely LOVES operating the microwave and I like that she practices number recognition, responsibility and safety (never touch the dishes inside the microwave, watch out so the door doesn't hit you in the head as it opens...).

2. Pour the very hot water into your jar and immediately place the plate on top.

 Little C helped pour the water into the jar, hence the goggles and oven mitts :-) Better safe than sorry!

3. Wait 2-3 minutes as the steam rises and condenses on the plate. Then place a handful of ice cubes onto your plate. Stress the importance of not touching or moving the plate at any point! Little C kept messing with the plate and we had too much steam escape the first time around and had to reheat our water and try again.

4. Watch what happens!
I have to admit, it's kind of anti-climactic because it doesn't really RAIN. It starts dripping down the sides, slowly. But while we waited to catch a drip (and subsequently yell "Drip!"), we talked about how the water at the bottom was hot and making steam. Little C already knew hot and steam went together because she often sees our hot food steaming. Then we observed that the plate was much colder than the water just like the air way up in the sky is much colder than down on the ground. The cold makes the steam turn back into water and when the plate is too full of water, it drips back down.

It may not have been super exciting, but Little C liked it so I have to call it successful!


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