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Which of the following metals will not replace copper from its salt solution :-

Best way of disposal of e-waste is___.

a) The molecule which we consume during respiration and is released during photosynthesis.

b) The red coloured element which we use to make matchboxes.

c) The pale blue gas which forms a layer that absorbs sun's UV radiation.

Fill in the blanks.​

​(a) The slow process of conversion of dead vegetation into coal is called__________.

​(b) Coal and petroleum are formed from the dead remains of organisms and are known as __________.

​(c) The black thick liquid with __________ smell is known as coal tar.

​(d) During the processing of coal to get coke, coal tar and __________ are also obtained.

​(e) The process of separating the various constituents of petroleum is known as __________.

​(f) Excessive burning of fossil fuels is a major cause of __________.

Metal salts are:

Rayon is chemically made by treatment of:

Air can be regarded as:

After a science lesson on 'Man-made materials', a class of pupils grouped as P, Q, R, and S made the following statements about recycling.

P- Recycling reduces pollution.
Q- Recycling makes the environment unfit for living things.
R- Recycling helps to conserve energy.
S- Recycling results in wastage of natural resources.

Which groups have made the correct statements?

Fill in the blanks :

(a) ______________is formed when wood is burnt in a limited supply of air.

(b) Coal is a _______________ form of carbon.

(c) __________________ is the most inferior form of coal.

(d) Wood charcoal is a _______________conductor of heat and electricity.

(e) __________________is used in making black shoe polish

Write the names of the following compounds.

a) CO

b) $N_{2}O$

c) $N{O}_2$

d) $PC{l}_5$

When sulphur (S) reacts with oxygen gas (O₂), it produces

What is the major source of fresh water in the city/town?

Incomplete combustion of carbon based fuels like coal, wood causes -

In 1911, the physicist Ernest Rutherford discovered that atoms have a tiny, dense nucleus by shooting positively charged particles at a very thin gold foil. A key physical property which led Rutherford to use gold was

What is the limiting value of Los Angeles abrasion value $\left(in\%\right)$ for wearing courses when these aggregates are to be used for concrete making ?

Write the properties of anode rays.

What will be the value of variable coefficients d, e, f, and g are considered for balancing the chemical equation.

Explain how the use of pesticides in agriculture causes water pollution.

Question 10

List the steps to conserve the resources.

Is hydrogen a halogen

Which one of the following is an example for soap?

What is meant by explosive combustion (or explosion) ? Give one example of explosive combustion or explosion).

When a chemical in a solution form or in a fused state breaks into simple elements by the passage of electric current, the process is called __________ .

Which of the following can be used as a method for secondary oil recovery?

1) Water flooding

2) Surfactants injection

3) $C{O}_2$ injection

4) Microbial injection

The total number of electrons having m = 0 in potassium atom is

Question 4

Give examples which indicate that nylon fibres are very strong.