Fun with Science – The Colorful Chaos of LED Bulbs

Continuing our series of Fun with Science, here is a special one – the colorful, glowing LED. These tiny, little things are so attractive, that you just can’t help but glow with ideas yourself! Can’t think of much? Don’t worry, here we are, to hold your hand through the basics!

Colorful Chaos of LED Bulbs


This activity is amusing for kids and adults alike, as it is fun and engaging. The basic idea is this – when two leads of an LED touch to the two poles of a battery, it lights up. What we are going to do is, we are adding a bunch of different LEDs with a coin cell battery into a container. When you shake the container, a random LED will light up! Let’s get started, shall we?


Things you will need for this project

  • At least 30 LEDs of different colors (the more, the better) – you can buy them online
  • A coin cell battery – you can buy them online or at your neighborhood electrical store.
  • A glass jar or any other clear plastic jar with a lid and  a mouth wide enough to put the coin cell battery inside

Let’s get down to making the game now

  1. Put all the LEDs in the jar.
  2. Drop the coin cell battery in the jar.
  3. Close the jar with the lid.
  4. Shake the jar and have fun!
  5. For better results, use a jar with diffused glass or plastic – the light of the LEDs will impart a glow to the jar.

Now, that the assembly is complete, and you know how it works, here are some fun ideas

  • You can make a game out of this. Have a point system in place – a red LED glowing gives you 0, a green one gives you 2, a blue one gives 5 points and so on. Take turns with your friends giving the LED jar a shake and keep scores.
  • Use it for an LED Ludo. Use the LED jar in place of the dice.
  • Have a spooky storytime at night in the dark, and use the lights for special effects!

Behind the scenes


So, what is happening here? Why don’t all LED bulbs glow when a battery is added to the jar full of LEDs? Well, the answer is quite simple: the battery needs to make contact with the terminals (leads) of the LED in order to light it up. If you took some time to play with the LED, you will realize that the LED lights up only one way: the longer lead of the LED needs to be connected to the positive side of the battery while the shorter lead to the negative side. This property decreases the probability of more number of LEDs being lighted up in the jar! Kind of mathematics, huh!? By the way, the LED is a diode, but one emitting light. In electronics,a diode is an electronic component that allows electric current to pass only in one direction, like a one way valve. This makes the Light Emitting Diode (LED) a polarity-sensitive bulb, if you connect wrong way, it will not light up!

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