chemistry studies the properties of matter and energy and how they interact with each other. in fact physics is also defined in the same way. chemistry and physics are an integral part of physical science. chemistry specifically studies the properties of the substances and their interactions with different types of matter, especially when they involve electrons.
chemistry is all around you if you notice. chemical reactions are taking place within our body, and outside in our natural environment all the time. however, we may not know about it unless we study or read about them, and then understand them. most of the chemical reactions are not visible to our naked eye.
chemistry is basically the study of everyday chemicals that are very much present around us and available, and that which can be applied in real life. these chemicals can be applied in many ways like in the kitchen. the kitchen is the ideal lab where people can experience various chemical reactions and even study them. they need not do anything special. they can simply do what they do in the kitchen everyday and still observe the chemical reactions that occur.
a simple task like boiling of water is a chemical reaction. we all know that water boils at 100 degrees centigrade. when we boil water everyday, we can observe this.
tamarind is a simple ingredient used in cooking in several dishes. it gives that extra tangy taste that you are looking for. however, when you cook or store tamarind in aluminum container, it releases certain types of chemicals into foods. when you learn about this, you would avoid cooking tamarind based substances in aluminum vessels, or storing tamarind in an aluminum container. a saturation point is when the water cannot dissolve anymore sugar or salt. this is why food ends up tasting very salty or sweet as it can take in no sugar or salt.
checking the temperature when we feel feverish using a thermometer is a simple chemical process we do sometimes. the mercury in the thermometer rises if the body temperature is high. when we touch certain chemicals like chlorine we can burn the skin. this is because of the chemical properties of these chemicals that are causing this burning sensation.
chemistry comes in use for killing pests and rodents at home. when we use naphthalene balls at home we are using a product of chemistry. many of us use pickling as a method to preserve vegetables. pickling is a simple chemical process that involves the process of osmosis.
1.should
2. must
3. shall
4. should/ ought to
5. could/ will
6. have to
7. need not
8. was not able
9. must
10. don’t have to
Объяснение:
1. If you prefer a relaxing holiday you _SHOULD__ choose a resort.
2. All the tourists around _MUST__ get a visa.
3. It’s very stuffy in the room,_SHALL__I open the window?
4. You__SHOULD/OUGHT TO_ make a little less noise.
5._COULD/WILL__ you help me?
6. All the students_HAVE TO__ wear school uniform at school.
7. You_NEED NOT__ take a heavy luggage on board the plane.
8. Sorry, I__WAS_ not_ABLE__ to visit the museum last night, I was very busy.
9. They_MUST__ be at home at this time. They usually come at 19:00.
10. You_DON'T HAVE __ to wait at the airport walking round your city.
