myclass24
myclass24your class. your pace.
Q&A BANK

every question.
answered.

1,376 answers across CBSE, ICSE, and State boards — Class 1 to 12, every subject.

CBSEICSEState
SUBJECT
CLASS

Filtered results

1,376 TOTAL
ScienceClass 8CBSE

Paheli bought a statue made of copper. To her surprise it acquired a dull green coating after a couple of months. Explain the reason.

Green coating on copper statue is the mixture of CU(OH)2 and CUCO3 which are formed due to reaction of moisture and copper.

ScienceClass 8CBSE

Which of the following metals can displace the other two metals from their salt solutions?

Zinc

ScienceClass 8CBSE

Which liquid metal is used for making thermometers?

Mercury

ScienceClass 8CBSE

Why are bells made of metals?

Metals show sonorous property hence they are used in making bells.

ScienceClass 8CBSE

Zinc sulphate forms a colourless solution in water. Will you observe any colour on adding copper turning in it?

There will no change as displacement reaction will not take place.

ScienceClass 8CBSE

A purple coloured non-metal forms a brown solution in alcohol which is applied on wounds as an antiseptic. Name the nonmetal.

Iodine

ScienceClass 8CBSE

Which non-metal is used to disinfect water?

Chlorine

ScienceClass 8CBSE

Name two major non-metals which are present in fertilisers and enhance the growth of plants.

nitrogen (ii) phosphorus

ScienceClass 8CBSE

Which non-metal is essential for our life and all living beings inhale it during breathing?

Oxygen

ScienceClass 8CBSE

Name two soft metals which can be cut with a knife.

sodium (ii) potassium

ScienceClass 8CBSE

Which of the following property is not responsible for copper to be used as electrical conduction wires? (a) ductility (b) colour (c) good conductor of electricity it is solid

Answer is (b) colour

ScienceClass 8CBSE

Generally metallic oxides are basic and non-metallic oxides are acidic in nature. Solution of which of the following oxides in water will change the colour of blue litmus to red? (a) sulphur dioxide (b) magnesium oxide (c) iron oxide copper oxide

Soln: Answer is (a) sulphur dioxide Explanation: Sulphur forms Sulphur-di-oxide which is acidic in nature and it will convert blue litmus to red.

ScienceClass 8CBSE

Which of the following non-metals reacts and catches fire on exposure to air? (a) phosphorus (b) nitrogen (c) sulphur (d) hydrogen

Answer is (a) phosphorus

ScienceClass 8CBSE

The metal which produces hydrogen gas on reaction with dilute hydrochloric acid as well as sodium hydroxide solution is (a) copper (b) iron (c) aluminium sodium

Soln: Answer is (c) aluminium Explanation: Aluminium reacts with dilute HCl as well as NaOH to produce Hydrogen Gas.

ScienceClass 8CBSE

Which of the following reacts with cold water vigorously? (a) carbon (b) sodium (c) magnesium sulphur

Answer is (b) sodium Explanation: Sodium reacts vigorously with water, hence it is stored in kerosene to avoid reaction of sodium with moisture in the atmosphere and oxygen.

ScienceClass 8CBSE

Metals generally react with dilute acids to produce hydrogen gas. Which one of the following metals does not react with dilute hydrochloric acid? (a) magnesium (b) aluminium (c) iron (d) copper

Answer is (d) copper Explanation: Less reactive metals like Copper, gold and silver does not react with dilute HCl to produce Hydrogen gas.

ScienceClass 8CBSE

Metals are generally solid. Which of the following metals is in the liquid state at room temperature? (a) mercury (b) silver (c) aluminium sodium

Answer is (a) mercury

ScienceClass 8CBSE

Metals are generally hard. Which of the following metals is an exception and can be cut with a knife? (a) iron (b) sodium (c) gold magnesium

Soln: Answer is (b) sodium Explanation: Sodium is highly reactive metals which looks soft and can be cut into pieces by using knife.

ScienceClass 8CBSE

Materials which can be drawn into wires are called ductile. Which of the following is not a ductile material? (a) silver (b) copper (c) sulphur aluminium

Soln: Answer is (c) sulphur Explanation: Ductility is the property of metals. Here Sulphur is non-metal which is not have ductile property.

ScienceClass 8CBSE

Boojho has learnt that non-metals on beating with a hammer are generally broken into pieces. Which of the following is a nonmetal? (a) iron nail (b) aluminium wire (c) copper plate piece of coal

Soln: Answer is (d) piece of coal Explanation: Iron, Copper and aluminum are metals whereas coal is a non-metal hence answer is (d) piece of coal.

STILL STUCK?

Get a tutor for just your question.

One-on-one help, verified tutors. Matched within 24 hours.

Get Started →