The oldest glue in the world is over 8,000 years old and comes from a cave near the Dead Sea. Today, we have enough types of tape and glue to build and repair almost anything. But what gives glue and tape their stickiness? And is one stronger than the other? Elizabeth Cox explores the world of adhesives.
Pick an activity or two and share what you have learned.
- This is a vocabulary rich video. Create a mini dictionary to go along with the video.
- Write a short speech from the point of view of tape or glue explaining why it is better than the other.
- Who invented Scotch Tape? Do some research to answer this question.
- Why would you want to use duct tape to hold a chain of bowling balls instead of glue?
- Make a list of all of the the types of tapes and glues that you know about. Don’t forget those made by nature.
How Glass is Made
This process is interesting and a more interesting question is how did humans begin this process in the first place? Watch a video about glass from Mystery Doug and take a few notes as you watch.
What materials are used to make glass?
Glass is made from a mixture of sand, lime and soda. When these ingredients are heated together, they form a liquid glass. This liquid glass is made into sheets by cooling and flattening. To make objects like vases, craftsmen blow into a glob of liquid glass with the help of a long tube.
Plate Glass made by Rolling:
- Sand, lime and soda are heated together in a furnace to make liquid glass. Rollers are used to flatten glass into sheets, which are first cooled, then cut.
Plate Glass made by Floating:
- Liquid glass from a furnace is floated and slowly cooled on the surface of liquid tin. After the glass has cooled down, it is cut into pieces.
- Vases, ornaments and other intricate glass objects are made by a glass-blower. The glass-blower uses a metal blowpipe which has a glob of hot glass at the end of it. A glass blower then blows the soft glass into shape.
Glass has many uses:
- Glasses, window panes, mirrors are few of the many things that are made from glass. Glass is not only useful, but can look beautiful too. Windows made of stained glass are works of art.
- Other glass-making ingredients can include alumina, lead oxide, salt-petre and zinc oxide which are used to make different types of glass. In the production of plate glass, waste glass from a previous melt is also added, making up 5 to 40 percent of the mixture. Melting takes place in giant furnaces, from where molten glass is floated or rolled into sheets.
Watch this animated step video about glass from Mocomi
Draw a picture timeline/use pic collage showing several of the different glass making process. Include at least 3 science words in your visual.