Chemistry worksheets for class 8th

                         

 Chemistry worksheet  

                           fill in the blanks

Fabric /cloth made from both synthetic and natural fibre.

 spandex is another name of lycra

 rayon fibre is also called artificial Silk 

Electrical switches are made up of thermosetting plastics 

The process of combining Monomers to form a polymer is called polymerization

Rayon is a fibre Re generated from alkaline solution

 acrylic is often used as a substitute for wool 

Teflon is used as a coating on the surface of non stick frying  pans  nylon synthetic fibre is commonly used to make strong ropes 

 polyester are long chain Polymers made by Linking of several Easter units.

Thermosetting plastics are set into a particular shape cannot be remoulded. 

petroleum is the most common source for synthetic fibre

  Q1. write the importance of synthetic polymer in your life 

Ans- synthetic Polymers are important in our life because of multiple uses nylon is widely used in women's hoisery  and it is used to make carpet materials and fabrics the fabric is also used in umbrella sleeping back and tents it is used to make shirt, blouses.  rayon mixed with cotton is used to make bed sheet dresses aprons caps.

Q2. What is Polyester name the popular polyester

 Ans- polyester is made up of repeating units of a chemical called Easter terylene which is chemically known as PET is the most popular polyester all over the world because it can be easily blended with natural fibres like cotton.

Q3. Write an activity to show that synthetic fibres are stronger than cotton fibres

Ans- Take an iron stand with a clamp and a cotton thread of about 65 CM length by the thread to the clamp so that it hangs freely at the free and suspend a pan so that weight can be placed in it adv8 one by one still the thread breaks no down the total weight required to break the thread this weight indicates the strength of the fibre repeat the same activity with Threads and cottons and nylons you will observe that the weight required to break the thread of cotton and nylon is more than cotton synthetic fibres are stronger than cotton.