Tag: physical properties of metals and non-metals

Questions Related to physical properties of metals and non-metals

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

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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

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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

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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.

The non-metal having shining surface is:

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

  1. sulphur

  2. phosphorus

  3. iodine

  4. carbon

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Correct Option: C
Explanation:

It's because going down the group the size of the atom increases because of the shielding effect due to which the interaction between the atom and the outermost electron decreases.

 So these electrons on the surface of iodine become excited by absorbing heat energy from light. so when they release this energy and come to their normal state, they emit this light so it appears that they have a shining surface.

So, the correct option is $C$

At room temperature liquid non-metal is 

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

  1. Carbon

  2. Bromine

  3. Mercury

  4. Iodine

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Correct Option: B
Explanation:

At room temperature liquid non-metal is bromine.

Generally, non-metals are not good conductors of electricity. 

Which of the following is a good conductor of electricity?

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

  1. Diamond

  2. Graphite

  3. Buckminster fullerene

  4. Sulphur

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Correct Option: B
Explanation:

Graphite has a layered planar structure. Carbon atoms in the plane are bonded covalently with only three of the four potential bonding sites. The fourth electron is free to migrate in the plane making graphite electrically conductive.

Bromine is the only liquid non-metal.

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:
Bromide is only liquid non metal ,mercury is liquid metal crallium is liquid metal.

Which of the following does not conduct electricity in its molten state?

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

  1. Iron

  2. Magnesium oxide

  3. Lithium fluoride

  4. Sulphur

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Correct Option: D
Explanation:

Sulphur is a non-metal so it does not conduct electricity. Iron is a metal so it conducts electricity Magnesium oxide and Lithium fluoride are ionic compounds that contains ions which conducts electricity in molten state.