Younger children are most likely to be interested in something which is very hands-on, and gives results quickly. They probably won’t be interested in growing a crystal, and are probably a bit young for something like a robot building kit. Young kids will be most likely to enjoy a gross science kit, or a volcano kit. Also think about safety features when buying for younger children. Make sure they won’t eat anything they shouldn’t, or there are no small parts which could be dangerous.
We saw one on Play School (Aussie TV show) last week and it was pretty cool. Have a flat small-medium sized white dish. Fill it with water and put four M+Ms in it (red, yellow, blue, green) spread out on the edges. Watch the magic happen as the colour moves out of the M+Ms and towards the centre. None of the colours mix so you get four quarters of bright colour. – Amanda
This Rainbow Skittles science experiment can be done in seconds, making it a great way to try science at home even with the most easily distracted of toddler-sized assistant. All you’ll need to do is arrange Skittles in a circle on a plate and fill the middle with warm water. Then sit back and watch as the colours drain and mix with the water, creating a cool rainbow pattern in front of your eyes. Plus, any bonus Skittles = a tasty treat for you.
This experiment teaches kids about weather and lets them learn how clouds form by making their own rain cloud. This is definitely a science project that requires adult supervision since it uses boiling water as one of the ingredients, but once you pour the water into a glass jar, the experiment is fast and easy, and you’ll be rewarded with a little cloud forming in the jar due to condensation.
You won’t want to do this experiment near anything that’s difficult to clean (outside may be best), but kids will love seeing this “elephant toothpaste” crazily overflowing the bottle and oozing everywhere. Pour the hydrogen peroxide, food coloring, and dishwashing soap into the bottle, and in the cup mix the yeast packet with some warm water for about 30 seconds. Then, add the yeast mixture to the bottle, stand back, and watch the solution become a massive foamy mixture that pours out of the bottle! The “toothpaste” is formed when the yeast removed the oxygen bubbles from the hydrogen peroxide which created foam. This is an exothermic reaction, and it creates heat as well as foam (you can have kids notice that the bottle became warm as the reaction occurred).
Kids this age will probably enjoy a whole range of different science kits. It’s good to look for something which will help with what they are learning about at school. Pre-teens are becoming more and more independent, so it might be worth looking for an experiment kit which is simple enough for them to do alone, but still hard enough to keep them entertained and learning. 

Insect hotels can be as simple (just a few sticks wrapped in a bundle) or as elaborate as you’d like, and they’re a great way for kids to get creative making the hotel and then get rewarded by seeing who has moved into the home they built. After creating a hotel with hiding places for bugs, place it outside (near a garden is often a good spot), wait a few days, then check it to see who has occupied the “rooms.” You can also use a bug ID book or app to try and identify the visitors.
For this magic milk experiment, partly fill a shallow dish with milk, then add a one drop of each food coloring color to different parts of the milk. The food coloring will mostly stay where you placed it. Next, carefully add one drop of dish soap to the middle of the milk. It’ll cause the food coloring to stream through the milk and away from the dish soap. This is because the dish soap breaks up the surface tension of the milk by dissolving the milk’s fat molecules.

Lightning is essentially electrons moving uber fast between the sky and the earth—and with a few simple materials, you can use homemade static electricity (the reason behind your hair sticking up when you rub a balloon or go through a tunnel slide super fast) for DIY lightning. Figure how to recreate a family-friendly version of this spark by visiting activity blog Learn Play Imagine.