Wonderful ideas! As a former science teacher, science department chair and system-wide science supervisor,; I salute you! It is mothers like you who keep the spark of investigation going in the eyes of our children. I love, love love hands-on science! You are training the scientists of tomorrow…or maybe the artists…doesn’t matter, we need both! Suggestion: let them see how many drops of water they can get on a penny. All you need is a penny, a medicine dropper and water. Oh, and a very steady hand and table that doesn’t shake. Then fill a jar with water (almost to the top) and predict how many pennies they can put in until the water overflows. Good lesson in surface tension and cohesion. You will need a steady hand, sturdy surface and a lot of pennies! I have some others, but no enough space. 

Have fun exploring science around your house and backyard. Take pictures of your experiment steps and make a science experiment notebook to record your findings. It’s safest to work with a parent or other adult when performing science experiments, though. Always get permission before you work like a scientist, and ask an adult to help you with the experiment steps.
The word “oobleck” comes from a Dr. Seuss story where a young boy must rescue his kingdom from a sticky substance. But the neat part of this experiment is how oobleck reacts to vibrations. Put the oobleck over a subwoofer (on top a cookie sheet!) and watch it dance to difference frequencies. Your dancer will see how sound isn’t just about volume! Check out more of this awesome experiment from Tammy of Housing a Forest.
You could even step into the living room to have more scientific fun. Learn about static electricity with some tiny scraps of paper and a balloon. Blow up the balloon and tie it closed. Make a small pile of paper scraps on the floor, and rub the balloon back and forth several times on your hair or on a sweater. Immediately move the balloon to the paper and watch as the paper scraps cling to the balloon. Rub the balloon on your head or sweater again and then place it against the wall to see it stick there. This surprising sticking happens because you have moved electrons around and the balloon now has more of a negative charge, while the paper or the wall has more of a positive charge. Putting the two surfaces together makes the opposite charges stick to each other.

You don’t need a storm to see lightning; you can actually create your own lightning at home. For younger kids this experiment requires adult help and supervision. You’ll stick a thumbtack through the bottom of an aluminum tray, then stick the pencil eraser to the pushpin. You’ll then rub the piece of wool over the aluminum tray, and then set the tray on the Styrofoam, where it’ll create a small spark/tiny bolt of lightning!
This is an easy and fun kit to learn about science. Got it for a five year old. The concepts are easy to follow and so are the directions. Everything is pretty much provided in the kit in order to make the science experiments with the exception of some ingredients like vinegar or other acidic ingredients that can be easily found in one's pantry or fridge. You will need one paper plate and some Ziploc bags to store the powders provided after opening the package. For example - baking soda. Overall, we've enjoyed this science kit. My five year old asks to make a science experiment each day! Very fun and educational.
This celery science experiment is another classic science experiment that parents and teachers like because it’s easy to do and gives kids a great visual understanding of how transpiration works and how plants get water and nutrients. Just place celery stalks in cups of colored water, wait at least a day, and you’ll see the celery leaves take on the color of the water. This happens because celery stalks (like other plants) contain small capillaries that they use to transport water and nutrients throughout the plant.
Dry ice is already cool enough on its own (yes, pun intended) but it takes science to turn them a rad overflow of bubbles. When you add water, it changes the temperature of the dry ice, causing the ice to go from solid to gas. That’s where the fog and bubbles come from! Head to crafty blog Simply Modern Mom to get the full tutorial. But be careful: Dry ice can cause serious skin burns, so make sure your kids are well supervised and know not to touch the ice.
Call the emergency services straight away if anything goes wrong. However these are all well-tested and very safe for the ages provided by the manufacturers, so rest assured this is only a formality, but it is good to be safe and start young with proper preventative measures. After all, what you start now will set the example for what they grow up to be.
Geode Kits – For any child who thinks rocks are boring – a kit where they can break open their own geode is a great way to change their mind. National Geographic is a great choice if this is the type of kit you are looking for. Their products include hand-picked geodes and come with safety goggles and a stand for your child to proudly display their treasures. A great choice for children aged around 6 years old and above, they’re sure to be more interested in Earth science after this experiment.
What better way to teach your kids about science than with more than 70 experiments in a big bag? The Big Bag of Science contains scientific ingredients and a book of 30 pages filled with experiments like soda geysers, twisting tornadoes, growing jelly marbles, vanishing liquids, and more! The instructions are easy-to-follow and color-coded so your child will easily complete the experiment without any trouble. The book explains what’s going on in each experiment so they understand why and how things work.
Adults who are supervising experiments do not need to be science gurus. In addition to step-by-step instructions for each experiment, the detailed science guide included with this kit provides adults with "mind blowing science secrets" that help to answer questions about what's happening in each experiment. All of the materials and experiments involve basic scientific concepts associated with acidic and basic liquids and are arranged to present these concepts in sequential order. The descriptions included in the science guide give background information related to each reaction and offer questions that adults can ask to help encourage fun learning during experimentation.
There are many fun ways to get your children into natural science and Geodes are one way. This starter kit has 7 unique and fascinating ways to get discovered the mystery of the earth crust. Geodes are natural and a wonder to many who like to collect, but even as a one-off this is a great way to get kids thinking. This is fun and the breaking aspect always makes things interesting for those that need some initial enthusiasm.
Not only will your kids build these physics machines, but they’ll also learn about the theories and facts behind each by understanding Newton’s Laws. For ages 8 and up, the Engino Newton’s Law Kit will teach your kids the effects of potential and kinetic energy by conducting one of the 8 included experiments. By the end, they’ll understand how energy is transferred from one car to another during a crash, or how an object gets catapulted from its machine.

The good news is that your white lab coat doesn’t have to sit in the closet collecting dust. There are a lot of fun, simple, and hands-on science projects families can do together to learn and understand some of the basic principals of the natural world. And they’re not just for kids: even moms and dads will get a kick out of these 10 family-friendly science experiments!
Put the pencil across the top of a jar so that the string hangs down the middle of the jar. If it hangs down too far, roll the string around the pencil until the string is not touching the sides or bottom of the jar. The string will act as a seed for the crystal. Any type of jar will do, but canning jars are best since they can endure the hot temperatures. Tall skinny olive jars are also nice because they don’t use up so much of the liquid.