Need for Classification

Q.

Water is a bad conductor of heat because

1. It has excess free electrons.

2. It has high pH.

3. It lacks free electrons.

4. It has low pH.

Q.

Water is a good conductor of heat.

1. True
2. False

Q. Which of these states of matter cannot be compressed at all?

1. Gases
2. Solids
3. Semi-solids
4. Liquids

Q. Describe the effect of heat on solids, liquids and gases in terms of expansion.

Q. In departmental stores all brands of shampoos and soaps are kept together, while all pulses and kitchen items are kept under the same category. What is the reason behing this?

1. It is a rule.
2. To confuse the customer.
3. It looks better when arranged in that manner.
4. It is a sorting technique that helps the customer.

Q. Why do we need to group materials? Give 3-4 reasons.

Q. The thermo emf of a thermocouple varies with the temperature theta of the hot junction as E=a theta +b theta square V Where the ratio of a and b is 700^°C. If the cold junction is kept at 0^°C, then the neutral temperature is

Q.

Is Brick a good thermal conductor

Q.

How can you classify material based on its appearance? Give one example each

Q.

5. Give three common characteristics of materials.

Q.

One material can't be used for making different kinds of objects.

1. True

2. False

Q.

Petrol and kerosene are miscible liquids.

1. True
2. False

Q. Which of the following combination is the odd one out?

1. Oil and water
2. Milk and water
3. Ink and water
4. Lime juice and water

Q. Which of the following methods is used to separate butter and buttermilk from curd?

1. Filtration
2. Churning
3. Evaporation
4. Sieving

Q. Write whether the following statements are true or false.

(c) Solids have the largest intermolecular space.

1. True
2. False

Q.

27. The three states of matter are classified based on the difference in the-------------- of their particles.

Q.

Why does a bulb burst, which has been glowing for a long time after a drop of cold water has fallen on it?

1. It is because glass conducts electricity.
2. It is because uneven cooling of the glass takes place.
3. It is because water freezes the bulb.
4. It is because glass conducts more heat.

Q. Which process takes place when particles in a solid begin to move apart slowly?

1. Subliming
2. Melting
3. Condensing
4. Boiling

Q.

Materials are classified as liquids if they have a specific shape.

1. Studying properties of materials becomes easy.

2. Helps in studying the colour of the materials.

Q.

Why do we need to separate substances?

Q. Write three different applications of expansion and contraction of materials.

Q. A single material cannot be used to make different kinds of objects.

1. True
2. False

Q.

Pick the odd material out: [1 MARK]

Cotton, sponge, wool, iron

Q. Give reason why on heating a sublimable solid , the molecules breaks free & escape from surfaces of the solid directly into vapour .

Q. The components of the mixtures are uniformly distributed in the ___________.

1. colloid
2. homogeneous mixture
3. heterogeneous mixture
4. suspension

Q. Why do we need to group materials? Give 3-4 reasons.

Q. Pair the given objects.

1. 
2. Opaque
3. 
4. Transparent
5. 
6. Translucent

Q.

You are supposed to sort the materials given to you into groups. Which of the following can be in similar groups according to the materials used for making them?

Pen, barbie doll, apple, chair, bench, phone and shirt.

1. Pen, barbie doll and phone
2. Shirt, barbie doll and phone
3. Pen, chair and bench
4. Shirt, pen and phone

Q. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Among the substances: gold, air, water and oil, partciles of which substance are most tightly packed and why?

Q. Chemists randomly arrange medicines for easy access.

1. True
2. False