Fireworks

Fireworks have a few different parts and they use different chemical compounds to create three kinds of results:

1. A tremendous "boom"
2. A bright light
3. Heat
All the parts work together to make their spectacular result. BOOM!

FACT The first fireworks were probably made in China out of green bamboo that was thrown into fire to scare spirits away. The story goes that a Chinese cook accidentally mixed three common kitchen ingredients (potassium nitrate, sulphur and charcoal) to make black powder and lighted it producing colorful flames. If the mixture was burned inside a bamboo shoot, there was a loud explosion.

     Some people think that Marco Polo first brought fireworks to the West and that the Crusaders helped spread the knowledge in the 14th century. The first recorded fireworks in England were at the wedding of Henry VII in 1486. Shakespeare mentions them and Queen Elizabeth I created a "Fire Master of England".

     By the 14th-15th century fireworks had spread throughout Europe. They were used in celebrations and in battles.

Read more about the history of fireworks here

Parts of a Firework

These are stars.

     An aerial firework is a shell that has four parts:

1. Container - Usually paper, cardboard, or plastic combined with string and formed into a cylinder. The container holds the stars, charges and fuses.
2. Stars - Spheres, cubes or cylinders made from special powder which are pressed or rolled. When lit, the stars produce a brilliant ball of fire. Stars come in many shapes and sizes.
3. Bursting charge - An explosive charge at the center of the shell that causes the shell to burst open, with a flash and explosion. The explosion sends the burning stars out in a particular pattern determined by the way the shell was packed by the pyrotechnician, creating the colorful effect the crowd sees and hears.
4. Fuse - Provides a time delay so the shell explodes at the right height. Check out NOVA's Anatomy of a Firework.

     An aerial firework also needs:

1. Lifting Charge- Located just below the shell is a small cylinder that contains the lifting charge that launches the shell into the air.
2 . Mortar - Long tubes made of cardboard, fiberglass, plastic or metal from which shells are launched. Mortars are often placed in sand or dirt.
          Now you are ready to visit a Fireworks Factory.

     A computer sends an electric signal that lights a fuse that is part of the firework. This fires a lift charge that launches the shell out of the mortar. This also lights another fuse called a time fuse.

     The amount of black powder and the length of the time fuse determine how high the shell will go and when it will explode. When the firework reaches the desired height, the time fuses lights the bursting charge This releases the fine metal powders of the stars in all directions based on the way the shell was packed and this charge lights the outside of the stars, which begin to burn with bright showers of sparks. The electrons in these metal particles become hot and excited, giving off light, called photons. Different metals give off different colors of light. There may also be chemicals that make crackles or whistles. After bursting, the display may last for about 5 seconds.

     The tremendous booms that you hear are made of the rapid release of energy into the air. This air expands faster than the speed of sound and produces a shock wave called a sonic boom. Flash powder makes the noise.

     The bright white light is given off by the chemical element, magnesium. This happens when the magnesium is suddenly exposed to oxygen which causes it to burn. Other elements can be used such as aluminum, titanium, zinc, or iron.    

Which chemicals make which color
http://www.scifun.org/CHEMWEEK/fireworks/fireworks.htm

FACT Deep blue and purple are the most difficult colors to make. Their chemical reaction has to be perfect. Blue and green are a challenge for pyrotechnicians because the chemicals used are very toxic (poisonous) . Orange is the easiest color to make.

NH4ClO4
This is the chemical abbreviation for
ammonium perchlorate.
Here is the entire Periodic Table of the Elements.

     Fireworks are made to burst at different heights. This depends on the size of the shell and how the fireworks are packed.

- 3 to 4 inch shells travel to about 300 - 400 feet.

- 5-6 inch shells travel 400 - 600 feet

- 8 inch shells travel 800 -1000 feet

- 10 - 12 inch shells travel 1000 - 1300 feet.

     Did you know that there are designers of fireworks shows? We learned about the pyrotechnician, the person who makes the shells, but there are other important people involved in a fireworks show.

     Many things must be considered: budget, theme, music, weather and location are just a few.

It can take about 100 hours to plan a 25 minute show!!! Uncover more designing tips.

     Every year nearly half of the more than 8,000 people who suffer injuries caused by the personal use of fireworks are children. A third of the injuries are caused by illegally obtained fireworks, and burns account for half the injuries.
FACT An ordinary sparkler burns at a temperature of more than 1000°C! . OUCH!

Here are some safety rules that all pyrotechnicians follow: Wear safety glasses. Never use fireworks indoors. Read more