Science experiments that you can carry out with kids at home should not and need not be expensive. Science is a great practical subject and one you can have a lot of fun with whether you homeschool or not. Science experiments are a great way to spend some quality fun time with your child or children and have fun learning with them. I have chosen four experiments that you can do easily using equipment and resources commonly found in most homes.Experiment One: Sink or FloatUsing a sink or bucket outside if you prefer fill with water leaving approximately 5cm empty. Collect some common objects e.g. a nail, pencil, raw egg, ruler, apple, toy boat, paperclip and a rubber Ball. Draw up a table with 3 columns with the headings ITEM, SINK and FLOAT. Predict whether the item will sink or float in one colour or with a tick. Place each item slowly into the water and record on your table what actually happens (use a different colour or cross). Try some different objects and add them to your list - do you get better with your predictions? When you finish the experiment try using a science book or website to investigate why you got the results you did for each object.Experiment Two: Quick Grip ReflexAll you need for this experiment is a ruler (preferably 30cm), pen and paper and one or more friends.1) Grasp the ruler with your thumb and forefinger at the end with the highest measurement. 2) Hold the ruler at head level with your arm extended away from your body. 3) Ask one of your friends to try to catch the ruler with their fingers as you drop the ruler. 4) Your friend positions their thumb and pointer finger (slightly open) at the lower end of the ruler. 5) Release the ruler and get ready to record their results. 6) Write down the measurement where your friends thumb grabbed the ruler. 7) Try this with the rest of your friends and record their results. 8) Now let one of your friends hold the ruler and let you have a go.Who had the quickest reaction? The person who catches the ruler at the lowest end of the ruler has the fastest reflexes. Which sense are you using to try and catch the ruler? Hint: SightExperiment Three: VolcanoUse can use baking soda and vinegar to create an awesome chemical reaction! You will need some baking soda (important to make sure it's not baking powder),vinegar, a large container and a cloth or some paper towels just in case you make a big mess! Perhaps consider this as an outside activity!Instructions:1. Place some of the baking soda into your container. 2. Pour in some of the vinegar 3. Watch as the reaction takes place!What's happening? The baking soda (sodium bicarbonate) is a base while the vinegar (acetic acid) is an acid. When they react together they form carbonic acid which is very unstable, it instantly breaks apart into water and carbon dioxide, which creates all the fizzing as it escapes the solution.Why not have a go at making a volcano using your craft skills and give a volcano demonstration at a science fair - don't forget some red food colouring to be really impressive!Experiment Four: Raw or Boiled Egg?How do you tell the difference between an egg that is raw and one that is hardboiled without breaking them? Answer: It's all in the gravity! For this experiment you will need two eggs, one hard-boiled and one raw of course. Make sure that the hard-boiled egg has been in the fridge long enough to be the same temperature as the raw egg or your experiment may not work properly.Instructions:1. Spin the eggs and watch what happens, one egg should spin while the other should wobble. 2. You can also try lightly touching each of the eggs while they are spinning, one should stop quickly while the other will keep moving after you have touched it.What happened? The raw egg's centre of gravity changes as the white and yolk move around inside the shell, causing the wobbling motion. Even after you touch the shell lightly it will continue to move. This is because of inertia causing the raw egg to spin even after you have stopped it. In contrast the hard-boiled egg spins rather than wobbles and will stop when you touch it because of the solid white and yolk.Older children can be encouraged to write up their experiments in a notebook by writing an equipment list, a method, recording their results and then writing a discussion to explain what happened.