1. Why do solids have a fixed shape?
2. Why do liquids flow?
3. Write two differences between liquids and gases.
4. When do we say that liquids are miscible?
5. What is a physical change? Give two examples.
6. What is a chemical change? Give two examples.
7. Give three characteristic features of a chemical change.
Answers
Ans 1 :- Solids have fixed shape because in solids the atoms are bonded tightly and there is very very less space in between atoms. So they have a definite shape and size.According to kinetic theory of energy, the intermolecular spaces between molecules of solids are very less and so have strong intermolecular force and thats why the molecules do not actually move and just vibrate which is cause that they have definite shape and volume.I hope you understood it.
Ans 2 :- Liquids have no fixed shape and their particles move over each other. This is due to their intermolecular force of attraction which is not that much strong compared to solids.
Ans 3 :- Liquid :-
1. No definite shape. Liquids attain the shape of the vessel in which they are kept. But have a fixed volume.
2.Compressible to a small extent.
3.These particles have a greater space between them.
4.The force of attraction between liquid
particles is less than solid particles
5.These particles move freely.
Gases :-
1. Gases have neither a definite shape nor a definite volume.
2.Highly compressible
3.The space between gas particles is the greatest.
4.The force of attraction is least between gaseous particles.
5.Gaseous particles are in a continuous, random motion.
Ans 4 :- Two liquids are said to be miscible if they completely mix with each other. That means a distinct layer between two liquids will not form when you have a solution that is labeled miscible.
Ans 5 :- Physical changes are those changes in which no new substances are formed. Example: Breaking of glass, freezing of water and tearing of paper.
Ans 6 :- A chemical change is the one in which formation of one or more new substances takes place. The new substance formed has different chemical composition and chemical properties from that of the starting material. Also the original material cannot be recovered easily. In simple terms, most of the chemical changes are irreversible. For example when lime is added to water, the temperature of water increases and water almost starts boiling. A substance called slaked lime is produced during this change. Hence, it is a chemical change. The following chemical equation can be used to represent the chemical change:
CaO + H 2 O → Ca (OH) 2 + Energy
Ans 7 :- Following are the two features of a chemical change:
(i) A new substance is formed and has different properties from the original substance.
(ii) Energy in the form of heat and light is either absorbed or released during the change.
(iii) Change of Temperature.
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Answer:
1)solid didn't have fixed shape
2)the force of the water particles areso water flow less than solid particles
3)liquids :1)liquid have less space, liquid contain more energy source, gases:gases have more space, it have so many gases like helium
4)when we added soap then the water is miscable
5)physical change is change but not chemical combination examples :melting of the ice or gas
Explanation:
1) because solid is not a combination of gases
2)explained in answer
3)tgis can't be bothered
4)because we the experiment in science
5)we can easily say about That like when we stand in sunny day we sweat that is physically change and sorry I didn't saying other 2questions because I am going to shop sorry plzzz