Question

please help me with this
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Answer 1

Answer:

Your ans will be:

A.Viruses are non-living when they are outside the host cell as they don't have any cellular machinery of their own. ... They take over the host cell machinery to replicate themselves, killing the host. That's why they are considered as link between living and non-living.

B. Farmers are required to implement a crop rotation that maintains or builds soil organic matter, works to control pests, manages and conserves nutrients, and protects against erosion.

C. 1) Mercury is the metal which is liquid at room temperature.

2) Bromine is the non metal which is liquid at room temperature..

3) Potassium is the most reactive metal.

D. Sound cannot travel through a vacuum. A vacuum is an area without any air, like space. So sound cannot travel through space because there is no matter for the vibrations to work on it.

Hope so it will help you..✌️

Answer 2

★ Required Answers ★

A. Why are viruses considered a link between living and non-living world?

$\longrightarrow$ Viruses are neither living nor non-living, this means they show the characteristics of both living as well as non-living beings. They multiply and replicate only in host cells and don't show any signs of life outside a living cell, that's why viruses considered a link between living and non-living world.

B. Why is crop rotation practiced by the farmers?

$\longrightarrow$ Crop rotation is practiced by the farmers so that the soil can regain its nutrients naturally. If the same crop will be grown again and again then soil will become deficient in any of the nutrients.So, crop rotation is practiced by the farmers in which crops are grown alternately in the same field.

C. Name the

• metal which is liquid at room temperature.
• metal which is liquid at room temperature.non-metal which is liquid at room temperature.
• metal which is liquid at room temperature.non-metal which is liquid at room temperature.most reactive metal.

$\longrightarrow$ (i) Mercury (Hg)

(ii) Bromine (Br)

(iii) Potassium (K) [ As it lies at the top of the reactivity series ]

D.How can you show that sound cannot travel through vaccum?

$\longrightarrow$ For this we'll do an experiment to prove that:

✿ Materials required :–

• A jar
• a phone

✿ Procedure :–

• Take a bell jar.
• Then put a cell phone into the jar.
• Then, pump out the air from the jar gradually by closing it.
• Call the number on that cell phone from the another cell phone.

✿ Observation :–

• You will notice that more and more air is removed from the jar, the sound of the phone ring becomes fainter and fainter.

• Since there will be a little amount of air, we'll be able to hear a little bit sound but when vacuum is created, no sound is heard.

✿ Conclusion:–

• So, from the above observation we get the information that sound can't travel in vacuum. It always need a medium to propagate.

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