Tag: composition of matter

Questions Related to composition of matter

The non-metal which is liquid at room temperature is:

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

  1. chlorine

  2. fluorine

  3. bromine

  4. iodine

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Correct Option: C
Explanation:

Bromine is the only non-metal which is liquid and diatomic molecule at room temperature. 

It is a dense, reddish-brown liquid evaporating at standard temperature and pressure to give an orange vapour. It is one of the only two elements on the periodic table that are liquids at room temperature other than mercury.

Hence, option $C$ is correct.

All non-metals are bad conductor of heat and electricity.

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:

Most of the non-metals are bad conductor of heat and electricity. But there are some non-metals which conduct electricity for example graphite. Due to presence of free electron in it.

Which type of elements show brittleness?

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

  1. Metals

  2. Non-metals

  3. Metalloid

  4. None of the above

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Correct Option: B
Explanation:

Non-metal are neither malleable nor ductile. Non metals are brittle.

Which of the following is not a property 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. Non-metals can be stretched into thin wires

  2. Non-metals are not ductile

  3. Non-metals are not malleable

  4. Non-metals break easily

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Correct Option: A
Explanation:

Non-metals are non-malleable and non-ductile. They are brittle. They break easily. So, they are regarded as brittle. They can't be stretched into mines or hammered into sheets.

Brittleness is a characteristic property of:

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

  1. gaseous non-metals

  2. liquid non-metals

  3. solid non-metals

  4. none of the above

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Correct Option: C
Explanation:

Brittleness is a characteristic property of non-metals. And here, we consider solid non-metals only. It is not applicable to liquid or gaseous non-metals.

Which is the lightest gas?

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

  1. ${N} _{2}$

  2. $He$

  3. ${O} _{2}$

  4. ${H} _{2}$

Show answer
Correct Option: D
Explanation:

Hydrogen and helium are the two lightest gasses,  they weigh so less that helium balloons and hydrogen dirigibles are able to float in the atmosphere.

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. 

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

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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.