A) Water droplets are seen on the outer part of metal tray. done clear
B) Water droplets are seen on the inner part of tray and inner part of the beaker. done clear
C) Water droplets are seen on the inner part of metal tray and outer part of the beaker. done clear
D) Water droplets are seen on the outer part of beaker only. done clear
View Solution play_arrowA) In flask I, a chemical change takes place. done clear
B) In flask II, a chemical change takes place and bubbles of carbon dioxide are seen. done clear
C) In flask II, a physical change takes place producing lots of bubbles. done clear
D) In flask I, salt reacts with lemon juice and forms a new compound. done clear
View Solution play_arrowquestion_answer3) Study the given Venn diagram carefully. 
The centre point X represents
A) Burning of paper done clear
B) Dissolving salt in water done clear
C) Boiling of an egg done clear
D) Bursting of a balloon. done clear
View Solution play_arrowA) Physical and reversible change done clear
B) Physical and irreversible change done clear
C) Chemical and reversible change done clear
D) Chemical and irreversible change. done clear
View Solution play_arrowA)
| (i) | (ii) | (iii) | (iv) | |
| Moist air | Grey | Corrosion | Chemical, reversible |
B)
| (i) | (ii) | (iii) | (iv) | |
| Air and water | Reddish brown | Rusting | Chemical, irreversible |
C)
| (i) | (ii) | (iii) | (iv) | |
| Oxygen in air | Green | Rancidity | Physical,, irreversible |
D)
| (i) | (ii) | (iii) | (iv) | |
| Nitrogen in air | Reddish brown | Galvanization | Chemical, irreversible |
question_answer6) Mark the incorrect statement.
A) Melting of wax is a physical change while burning of wax in a candle is a chemical change. done clear
B) Metals expand on heating while contract on cooling. Both are physical changes. done clear
C) Composition of matter changes during a chemical change while it remains same during a physical change. done clear
D) High and low tides in sea are the examples of non-periodic changes while growth of a tree is a periodic change. done clear
View Solution play_arrowquestion_answer7) Few changes are given below. Mark the correct option from the codes given below.
| (i) Milk is set to form curd. |
| (ii) Batter is steamed to form idlis. |
| (iii) Water is boiled to form steam. |
| (iv) Salt is dissolved in water to form solution. |
A)
| (i) | (ii) | (iii) | (iv) |
| Physical | Physical | Chemical | Chemical |
B)
| (i) | (ii) | (iii) | (iv) |
| Physical | Chemical | Physical | Chemical |
C)
| (i) | (ii) | (iii) | (iv) |
| Chemical | Chemical | Physical | Physical |
D)
| (i) | (ii) | (iii) | (iv) |
| Physical | Chemical | Chemical | Physical |
A) There was no difference in the contents of China dish before and after heating. done clear
B) Before heating, iron filings and sulphur powder could be seen separately but after heating the content became black. done clear
C) Before heating, the iron filings and sulphur powder could not be seen separately. done clear
D) Before heating, the contents were black and after heating, iron filings and sulphur could be seen separately. done clear
View Solution play_arrowquestion_answer9) What is common among the following phenomena?
| 1. Blinking of traffic lights. |
| 2. Rotation of blades of a fan. |
| 3. Swinging of pendulum of a clock. |
A) All are chemical changes. done clear
B) All are periodic changes. done clear
C) All are undesirable changes. done clear
D) All are irreversible changes. done clear
View Solution play_arrowA) In figure I, physical change is taking place while in figure II a chemical change is taking place. done clear
B) In figure I, a chemical change is taking place while in figure II a physical change is taking place. done clear
C) In both figures, physical changes are taking place. done clear
D) In both figures, chemical changes are taking place. done clear
View Solution play_arrowA) Tearing the sheet into pieces. done clear
B) Burning the pieces done clear
C) Both tearing and burning the pieces done clear
D) None of these. done clear
View Solution play_arrowA)
| P | Q |
| Reversible change | Reversible change |
B)
| P | Q |
| Irreversible change | Reversible change |
C)
| P | Q |
| Irreversible change | Irreversible change |
D)
| P | Q |
| Reversible change | Irreversible change |
A) Process 1 is a reversible, physical change while process 2 is an irreversible, physical change. done clear
B) Process 1 is an irreversible, physical change while process 2 is an irreversible, chemical change. done clear
C) Process 1 is a reversible, physical change while process 2 is an irreversible, chemical change. done clear
D) None of these. done clear
View Solution play_arrow| Column I | Column II |
| P. Digestion of food in our body | (i) Fast change |
| Q. Earthquake | (ii) Natural, desirable change |
| R. Falling of stone | (iii) Natural, undesirable change |
| S. Change of seasons | (iv) Slow change |
A) P-(iv), Q-(ii), R-(iii), S-(i) done clear
B) P-(iii), Q-(iv), R-(ii), S-(i) done clear
C) P-(ii), Q-(i), R-(iv), S-(iii) done clear
D) P-(iv), Q-(iii), R-(i), S-(ii) done clear
View Solution play_arrowquestion_answer15) Consider the following phenomena:
| (i) Forest fire |
| (ii) Growth of plants |
| (iii) Low and high tides |
| (iv) Occurrence of a rainbow |
| (v) Earthquakes |
| (vi) Opening of a morning glory flower. |
A) (i), (ii) and (iii) done clear
B) (i), (ii) and (v) done clear
C) (iv), (v) and (vi) done clear
D) (iii) and (vi) done clear
View Solution play_arrowquestion_answer16) Observe the given figure carefully and choose the correct statement, 
A) Processes (iii) and (iv) involve absorption of heat energy. done clear
B) Process (v) involves condensation and freezing. done clear
C) Processes (i) and (iii) evolve heat energy. done clear
D) Process (v) absorbs a lot of heat energy. done clear
View Solution play_arrowquestion_answer17) Swati classified a few changes occurring around us as shown in the table.
| No. | Changes | Type |
| 1. | Sharpening of pencil | Physical, reversible |
| 2. | Evaporation of water | Physical, irreversible |
| 3. | Opening of a bud | Chemical irreversible |
| 4. | Rusting of iron | Chemical reversible |
A) 2 and 3 only done clear
B) 3 and 4 only done clear
C) 1 and 4 only done clear
D) 3 only done clear
View Solution play_arrowquestion_answer18) Read the given statements and mark the correct option.
| Statement 1: While fixing a metal rim on a wooden wheel of a cart, the size of the metal rim is kept slightly smaller than that of the wooden wheel. |
| Statement 2: Metals expand on heating and contract on cooling. |
A) Both statements 1 and 2 are true and statement 2 is the correct explanation of statement 1. done clear
B) Both statements 1 and 2 are true but statement 2 is not the correct explanation of statement 1. done clear
C) Statement 1 is true and statement 2 is false. done clear
D) Both statements 1 and 2 are false. done clear
View Solution play_arrowquestion_answer19) Study the given Venn diagram. 
Identify points 1, 2 and 3.
A)
| 1 | 2 | 3 | |
| Melting of ice | Boiling of rice | Burning of a candle |
B)
| 1 | 2 | 3 | |
| Burning of paper | Rusting of iron | Cutting of fruits |
C)
| 1 | 2 | 3 | |
| Breaking of a glass | Baking a cake | Burning of LPG in kitchen |
D)
| 1 | 2 | 3 | |
| Tearing of paper | Evaporation of water | Making lemonade |
| I. Bubbles are formed in process 1 while no bubble formation takes place in process 2. |
| II. Process 1 is slow while process 2 is fast. |
| III. Process 1 occurs at \[{{100}^{o}}C\]only while process 2 can occur at any temperature. |
A) I and II only done clear
B) II and III only done clear
C) I and III only done clear
D) All of these. done clear
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The beaker and metal tray were then removed from the tripod stand and left on the table. After two minutes, which of the following can be observed? 
(i) Melting of ice (i) Cutting of paper (ii) Blowing of balloon (ii) Flowering of bud Which of the following is correct? 
Which of the following statements are correct? 
