Tag: chemistry

Questions Related to chemistry

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

Show answer
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

Show answer
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

Show answer
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

Show answer
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.

Iodine is a non-metal which has metallic lusture.

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

Show answer
Correct Option: A
Explanation:

Its because going down the group the size of the atom increases because of 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 lustrous surface.

A non-metal which is a good conductor of electricity is:

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

  1. graphite

  2. hydrogen

  3. sodium

  4. mercury

Show answer
Correct Option: A
Explanation:

1) Graphite is soft and slippery because there are only weak intermolecular forces between its layers. Graphite is a good conductor of heat and electricity.

2) Graphite can conduct electricity because of the delocalised (free) electrons in its structure.

3) These arise because each carbon atom is only bonded to 3 other carbon atomsHowever, in diamond, all 4 outer electrons on each carbon atom are used in covalent bonding, so there are no delocalised electrons.

4) These electrons in graphite are free to move through the structure.

Chlorine is greenish yellow gas.

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:

It is a pale green gas and is used in cleaning products. Chlorine is an greenish-yellow gaseous element. Its atomic number is 17, and is one of the class called halogens in the periodic table. Large concentration of chlorine are dangerous.

Graphite is the only non-metal which is 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. True

  2. False

Show answer
Correct Option: A
Explanation:
Graphite is composed of carbon atoms which are situated in layers. Because of that electron are free to move and conduct the electricity. Although it is a non-metal, good conductor of electricity. 

Non-metals are present in which state?

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

  1. Solid

  2. Liquid

  3. Gaseous

  4. All of the above

Show answer
Correct Option: D
Explanation:

Answer: all of the above 

Most of metal exist in two out of three states of matter at room temperature
Eg: gases- oxygen,  solid-carbon

Only bromine exist in liquid state at room temperature.