Tag: chemistry

Questions Related to chemistry

Non-metals have properties similar to that of metals.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

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Correct Option: B
Explanation:

Non-metals have properties similar to that of metals , This  Statement is false because:

Properties of metals : 

Metals are solid at room temp. 
They are generally hard and strong. 
They have metallic lustre. 
They have high melting and boiling points. 
They are good conductors of heat and eletricity. 
Metals are sonorous. 
Most metals have high tensile strength. 
They are malleable. 
They are ductile. 
They have high densities. 


Properties for non-metals: 

Non-metals are glasses or solids at room temp. except bromine. 
They are not as hard as metals and have low tensile strengths. 
They do not have lusture. 
They are bad conductors of heat and electricity. 
Non-metals are brittle, they are neither malleable nor ductile. 
They usually have low densities. 
They have low melting and boiling points. 
They are non-sonorous. 

Which of the following are uses of sulphur?

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Sulphur is used in preparation of conducting wires

  2. A mixture of zinc and sulphur on heating with sulphur produces a greyish residue of zinc sulphide

  3. Sulphur is an element belonging to VI A group

  4. Sulphur is a nonmetallic element.

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Correct Option: B,C,D
Explanation:

Zinc on heating with sulphur produces a greyish residue of zinc sulphide.
Sulphur is an element belonging to VI A group.
Sulphur is a nonmetallic element.

Plastic sulfur has no sharp melting point.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

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Correct Option: B
Explanation:

Amorphous or plastic sulfur is produced by rapid cooling of molten sulfur e.g. by pouring it in cold water. It has helical form and metastable at room temperature reverting to its crystal allotrope and have sharp melting point.

State whether true or false :

Diamond and iodine are non-metals which are lustrous.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

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Correct Option: A
Explanation:

In case of iodine, the large size of the atom results in low shielding of valence electrons. 


Upon absorption of light or heat by these electrons, the de-excitation of the absorbed heat from the surrounding emit light so it appears that they have lustrous surface.


The sparkling shine of the diamond comes from its cut, clarity, refractive index and reflection. 

The natural diamonds found from the earth is dull and dim. Total internal reflection partially provides the brilliance and shine to the diamond. 

When light strikes the diamond, it gets refracted and get separated into individuals colors. Diamonds normally have high refractive index thus providing a brilliant shine to the diamond.

Therefore Diamond , graphite & iodine are nonmetals which are lustrous because of their crystal structure.

Therefore, option A is correct.

Compare the physical properties of metals and non-metals in general with reference to melting point.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Both have low melting point

  2. Both have high melting point

  3. Metals have low melting point while non-metals have high melting point

  4. Metals have high melting point and non-metals have low melting point

Show answer
Correct Option: D
Explanation:

Metals have high melting and boiling point. Tungsten has the highest melting point where as silver has low boiling point. Sodium and potassium have low melting points. Non metals have low melting point.

Diamond and graphite are good conductors of electricity.

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Graphite is able to conduct electricity, due to delocalization of the pi bond electrons above and below the planes of the carbon atoms. These electrons are free to move, so are able to conduct electricity.
In diamond, all four outer electrons of each carbon atom are 'localized' between the atoms in covalent bonding. The movement of electrons is restricted and diamond does not conduct an electric current.
Thus, graphite is a good conductor and diamond is not. 
Option "B" is correct.

Which of the following is a good conductor of electricity?

chemistry metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Diamond

  2. Graphite

  3. Both A and B

  4. None of the above

Show answer
Correct Option: B
Explanation:

Diamond and graphite are allotropes of carbon. Graphite has carbon molecules held together by weak van der Waal's forces of attraction and they have loosely bound electrons which are responsible for conducting electricity, while diamond is the hardest and strongest material in which all the molecules are bound by strong bonding between carbon tetrahedrons held by strong forces of attraction and so, they do not have free or loosely bound electrons to conduct electricity.

By dropping a drop of water on a glowing electric bulb, it bursts. This is because glass is a _________.

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. good conductor of heat

  2. bad conductor of heat

  3. transparent substance

  4. good conductor of electricity

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Correct Option: B
Explanation:

1) The glass is actually an insulator. 

2) It doesn't allow the flow of electrons easily from atom to atom, as seen in substances like copper, and other metals which are excellent conductors of both heat and electricity. 

3) Insulators have electrons that are held tightly which means they aren't shared between other atoms.

Which of the following is a property of nonmetals?

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Low densities

  2. Low melting points

  3. Poor conductor of electricity

  4. All the three

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Correct Option: D
Explanation:
Non metals are poor conductor of electricity, low densities, low melting points, non lustrous, brittle in nature, non ductile and not malleable in nature.
So, answer is D.

Which of the following are properties of non-metals?

chemistry composition of matter physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Low melting point

  2. Poor conductor of electricity

  3. Low densities

  4. All of these

Show answer
Correct Option: D
Explanation:
Common Properties of non-metals-
  • High ionization energies.
  • High electronegativities.
  • Poor thermal conductors.
  • Poor electrical conductors.
  • Brittle solids - not malleable  or ductile.
  • Little or no metallic lustre.
  • Gain electrons easily.
  • Dull, not metallic-shiny, although they may be colorful.
  • Low melting point and densities.
  • Lower melting points and boiling point than the metals.