Tag: chemical bonding and structure

Questions Related to chemical bonding and structure

What is the electron sea model?

bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

  1. The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.

  2. Where electrons float free in a sea of salt water.

  3. The model of metallic bonding where electrons are fixed in place in a sea of metal atoms.

  4. A model depicting the different bonds that electrons can make.

  5. The model of metallic bonding where protons float free in a sea of electrons around metal atoms.

Show answer
Correct Option: A
Explanation:

(A) : The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.
This model proposes that all the metal atoms in a metallic solid contribute their valence electrons to form a "sea" of electron. The electrons present in the outer energy levels of the bonding metallic atoms are not held by any specific and can move easily from one atom to the next.

In metallic bonding the electricity conduction is due to the presence of :

bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

  1. lattice

  2. nucleus

  3. protons

  4. delocalized electrons

Show answer
Correct Option: D
Explanation:

The electrons can move freely within molecular orbitals, and so each electron becomes detached from its parent atom. The electrons are said to be delocalised. The metal is held together by the strong forces of attraction between the positive nuclei and the delocalised electrons.This is sometimes described as "an array of positive ions in a sea of electrons".

Ornamental gold is an alloy of gold and silver.

chemistry chemical bonding and structure alloys and their properties metals, alloys and crystals elements and compounds

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Gold as pure metal is too soft on its own and is therefore hardened by the addition of alloying element like silver for ornamental purpose.
option A is correct.

Which of the following pair of elements form alloy?

chemistry chemical bonding and structure alloys and their properties metals, alloys and crystals elements and compounds

  1. $Zn$ and $Pb$

  2. $Fe$ and $C$

  3. $Hg$ and $Ag$

  4. All of these

Show answer
Correct Option: D
Explanation:
Alloys are formed by metals whose atomic radii not differ by more than $15 \%$ so that the atoms of one metal can easily take up the positions in the crystal lattice of the other.
Thus all of these will be the correct answer.

The mixture of two or more metals is called a/an _______ .

chemistry chemical bonding and structure alloys and their properties metals, alloys and crystals elements and compounds

  1. solder

  2. mixture

  3. alloy

  4. amalgam

Show answer
Correct Option: C
Explanation:

The mix of two or more metals is called an alloy. the various properties of metals can be unproved by mixing two or more metals.

The alloy steel used for making automobile parts and utensils is called

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. nickel steel

  2. stainless steel

  3. tungsten steel

  4. chromium steel

Show answer
Correct Option: A

An alloy which does not contain copper is:

chemistry chemical bonding and structure alloys and their properties metals, alloys and crystals elements and compounds

  1. solder

  2. bronze

  3. brass

  4. bell metal

Show answer
Correct Option: A
Explanation:

Solder- an alloy of tin $(Sn)$ and lead $(Pb)$
Bronze-an alloy of copper $(Cu)$ and tin $(Sn)$
Brass-an alloy of copper $(Cu)$ and Zinc $(Zn)$
Bell metal-an alloy of copper $(Cu)$ and tin $(Sn)$
Therefore option A is correct

Select the correct alternative for the preparation of steel:

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. A - coal, B- limestone, C - iron ore

  2. A - coal, B - iron ore , C -limestone

  3. A - limestone, B - coal , C - iron ore

  4. A - iron ore, B -limestone , C - coal

Show answer
Correct Option: D
Explanation:

Making iron is the first step of production of steel. Iron is usually made from iron ore,limestone and coal. Limestone is added to iron before entering the blast furnace. The limestone reacts with acidic impurities called slag and floats on top of the molten iron where it is skimmed off.

Element present in the stainless steel is ______________.

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. Iron

  2. Chromium

  3. Nickel

  4. All of these

Show answer
Correct Option: D
Explanation:

Stainless steel also known as inox steel. It is an alloy of steel (Iron and nickel) with chromium 10.5%. It does not corrode readily, rust or stain. There are different grades of stainless steel. It is used where both the properties of steel and corrosion resistance are required.

Mark the incorrect statement.
a) Alloys with required properties can be made.
b) Alloys have properties different from constituent metals.
c) Alloys can never have carbon in it.
d) Alloy is a heterogenous mixture.

chemistry elements and compounds alloys and their properties metals, alloys and crystals chemical bonding and structure

  1. a, b

  2. c, d

  3. a, c

  4. b, d

Show answer
Correct Option: B
Explanation:

Alloys have properties which can different from the constituent metals. In fact it is possible to make alloys having required properties.

Alloy is a homogeneous mixture. Steel is an alloy of iron and carbon.