131. What is the formula of potassium ion whose configuration is same as the noble gas state?

1.K+
2.K2+
3.K2-
4.K-

Option “A” is correct
K+  is the formula of potassium ion whose configuration is same as the noble gas state.This means that potassium must have an electron configuration of 1s2,2s2,2p6,3s2,3p6
132. Which of the following is made up of Carbon only?

1. Kevlar
2. Lexan
3. Graphene
4. Spider silk

Option “C” is correct
Graphene is an allotrope of Carbon in the form of a two dimensional atomic-scale hexagonal lattice in which one atom from each vertex.
133. The inert gas which is substituted for nitrogen in the air used by deep sea divers for breathing, is-

1. Argon
2. Xenon
3. Helium
4. Krypton

Option “C” is correct
Hydreliox is a mixture of oxygen, helium, and hydrogen and is used for dives below 130 metres in commercial diving.
134. The rubbing surface of a matchbox has powdered glass and a little red ________________.

1. Antimony
2. Arsenic
3. Silicon
4. Phosphorus

Option “D” is correct
The rubbing surface of a matchbox has powdered glass and a little red Phosphorus.
135. Crystallisation is an example of?

1. Physical Change
2. Chemical Change
3. Chemical Reaction
4. Galvanisation

Option “A” is correct
Crystallisation is an example of physical change.
136. Vinegar and Baking Soda together produce ____________.

1. Copper
2. Carbon Dioxide
3. Copper Sulphate
4. Magnesium Oxide

Option “B” is correct
The reaction between baking soda (sodium bicarbonate) and vinegar (dilute acetic acid) generates carbon dioxide gas.
137. The resources which can be used continuously, year-after are called –

1. Biotic
2. Abiotic
3. Non-renewable
4. Renewable

Option “D” is correct
The resources which can be used continuously, year-after are called Renewable resources.
138. A balloon filled with helium rises in air because –

1. air exerts an upward force on the balloon
2. the balloon is weightless
3. helium is less dense than air
4. helium pushes down on the air below the balloon

Option “C” is correct
Air contains 78% of nitrogen which is heavier than helium. Therefore, a balloon filled with helium rises in air because helium is less dense than air.
139. German silver, an alloy, does not contain the metal –

1. Nickel
2. Zinc
3. Copper
4. Silver

Option “D” is correct
German silver is an alloy of having 60% copper, 20% nickel and 20% zinc. It is also known as Nickel Silver. Nickel silver is named for its silvery appearance, but it contains no silver.
140. Which of the following imparts a blue colour to glass?

1. Cobalt Oxide
2. Copper Oxide
3. Iron Oxide
4. Nickel Oxide

Option “A” is correct
The following metals imparts different colour to glasses- Cobalt oxide: deep blue colour; copper oxide: turquoise; chromium: dark green to black; cadmium sulphide: deep yellow etc.
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9 thoughts on “Chemistry”

  6. Dolly

    I Love chemical…it’s my favourite subject..mere iss mein se hmesha hi boht ache marks aate hai….and my interest is also in chemistry…

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