ROUND-UP 1 3. fill in the sentences with a suitable word for each blank space. 1. have many , among which being . chemistry studies molecules a. Polymers plastic disadvantages non-biodegradable b. Plastic polymers advantages non-biodegradable c. Plastic polymers disadvantages biodegradable d. Polymers plastic disadvantages biodegradable containing carbon. 2. Carbon combine together in a multiplicity of ways. 3. Organic are all around us and shape our world. 4. consist of smaller molecules bonded together. 4. or more sugars make up carbohydrates, which are 5. Characteristic chemical reactions of divided into and . a. Three complex oligosaccharides polysaccharides b. Two complex monosaccharides disaccharides c. Three simple monosaccharides polysaccharides d. Three simple oligosaccharides disaccharides molecules are determined by of atoms. 6. The two major classes of hydrocarbons are compounds and aromatic compounds. 7. made of can is the simplest aromatic compound. 8. In , oxygen-hydrogen molecules are linked to hydrocarbons. 2 choose the right option. 1. Polymers are organic molecules consisting of repeating units. a. b. c. d. 2. small molecules larger atomic large molecules smaller atomic large molecules smaller molecular small atomic larger molecular soften when and can be shaped when hot, harden when . a. Thermoplastics shaped thermosets heated c. Thermosets heated thermoplastics shaped b. Thermosets heated thermoplastics moulded d. Thermoplastics heated thermosets moulded 94 more wonders of chemistry 3 Answer the following questions. 1. Into how many groups are aliphatic compounds divided? ........................................................................................................................... 2. What is the difference between an addition polymer and a condensation polymer? ........................................................................................................................... 3. Why is synthetic rubber preferable to natural rubber? ........................................................................................................................... 4. What is a disadvantage of polymers? ........................................................................................................................... 5. What are proteins made up of? ........................................................................................................................... 6. How are carbohydrates produced? ........................................................................................................................... 7. What are the major roles of lipids? ........................................................................................................................... 8. What makes up nucleic acids? ...........................................................................................................................