Class 8 - Chemistry - Case Study Based Questions - #class8Science #cbseClass8 #eduvictors

Class 8 - Chemistry - Case Study-Based Questions

Chapter: Chemical Effects of Current

Directions: Read the following and answer the questions given below:

Case Study

Take out carbon rods carefully from two discarded cells. Clean their metal caps with sandpaper. Wrap copper wires around the metal caps of the carton rods to form electrodes and join them to a battery, Pour a cupful of water into a glass/plastic bowl. Add a teaspoonful of salt or a few drops of lemon juice to water to make it more conducting. Now immerse the electrodes in this solution. Make sure that the metal caps of the carbon rods are outside the water. Wait for 3-4 minutes, Observe the electrodes carefully.

Class 8 Science – Coal and Petroleum #class8Science #cbsenotes #eduvctors

Class 8 Science – Coal and Petroleum

Very Short Answer Type Questions

1. Name three useful products of coal.

2. Which product of coal is used as a reducing agent in the extraction of metals?

3. Name the process by which plant material (or vegetation) buried deep under the earth was slowly converted into coal.

4. Name the product of coal, which is a thick black liquid with an unpleasant smell.

CBSE Class 8 Science - Combustion and Flame - Worksheet-2 #class8Science #eduvictors #combustion

CBSE Class 8 Science - Combustion and Flame - Worksheet-2

Fill in the blanks with suitable words.

1. ________ gas in air is essential for combustion.

2. A chemical process in which a substance reacts with oxygen to give off heat is called __________.

3. During the process of combustion, _______ and light are given out.

CBSE Class 8 Chemistry - Metals and Non-Metals (MCQs) (#class8Chemistry)(#class8Science)(#eduvictors)

CBSE Class 8 Chemistry - Metals and Non-Metals (MCQs) 

Q1: All metals are solids except: 

(a) Sodium

(b) Calcium

(c) Mercury

(d) Copper

Q2: Which of the following metal does not react with dilute Hydrochloric acid?

(a) Iron

(b) Sodium

(c) Magnesium

(d) Copper

CBSE Class 8 - Chemistry - Synthetic Fibres and Plastics - Plastics Uses and Its Impact on Environment (Q and A)(#class8Science)(#eduvictors)

CBSE Class 8 - Chemistry - Synthetic Fibres and Plastics - Plastics Uses and Its Impact on Environment (Q and A)

Q1: What is a plastic?

Answer: Plastic is also a polymer like the synthetic fibre. All plastics do not have the same arrangement of units. In some, it is linear, whereas in others it is cross-linked.

Q2: What are the main properties of plastics?

Answer: 

① Plastic is easily mouldable in all types of possible shapes. 

② Most plastics are light, chemically stable and do not rust. The weight of plastic is less when compared to that of metal.

③ Some types of plastics are good insulaters and have low thermal conductivity.

④ Plastic can be recycled, coloured, reused, rolled into sheets or made into wires.

⑤ Most plastics have poor heat resistance.

⑥ Plastics have good durability (lasts longer).

CBSE Class 8 - Science - Metals and Non-Metals (Question Bank) (#cbsenotes) #eduvictors

Metals and Non-Metals (Question Bank)

Name the following questions:

1. Name some common non-metals used in our daily life.

2. Hardest naturally occurring substance.

3. Property of metals which make them useful as electric wires.

4. Non – metal which has a metallic lustre.

5. Two non-metals which are soft solids.

6. Non-metals do not conduct electricity or heat except for one. Name it.

7. An allotrope of carbon which is as tensile as steel.

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