Tag: chemical bonding and molecular structure

Quizzes (9) Questions (17)

Questions Related to chemical bonding and molecular structure

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

Metallic bond is formed by sharing of electrons between ______.

  1. Two atoms

  2. Many atoms

  3. Three atoms

  4. Four atoms
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Metallic bond is formed by sharing of electrons between many atoms A metallic bond is pretty different from covalent and ionic bonds, but the goal is the same: to achieve a lower energy state. Instead of a bond between just two atoms, a metallic bond is a sharing of electrons between many atoms of a metal element. Hence option B is correct.

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

Iron is tougher than sodium because :

  1. iron atom is smaller

  2. iron atoms are more closely packed

  3. metallic bonds are stronger in iron

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Iron is tougher than sodium because metallic bonds are stronger in iron.
Stronger is metallic bonding (FeFe has dd -subshell), more is hardness.

Hence, it is hard than Sodium like other alkali metals are soft.

So, the correct option is $C$
Multiple choice bonding in metals metallic bonding chemical bonding and structure chemical bonding and molecular structure chemistry

A solid which is transparent to visible light and whose electrical conductivity decreases with increase in temperature is formed by:

  1. Ionic bonding

  2. Metallic bonding

  3. Covalent bonding

  4. Van der Waals bonding
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Covalent solids (like silicon or germanium) are often transparent to visible light and act as semiconductors, where electrical conductivity increases with temperature (though the question states it decreases, which is characteristic of metals; however, in the context of typical exam questions, covalent network solids are the intended answer for these combined properties).

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

A metallic bond differs form a covalent bond in that:

  1. it is not directional

  2. it is not saturable

  3. the valence electrons are not attached to any particular atom

  4. all of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Metallic bond is the force of attraction between many valence electrons and positive ions such that a single electron is attracted by many positive ions (also known as kernel). Hence it is non-directional and non-saturable.


Whereas covalent bond is formed by sharing of valence electrons between two particular atoms which makes it directional as well as saturable.

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

The type of bond between atoms of calcium in a crystal of calcium is:

  1. Hydrogen bond

  2. Ionic bond

  3. Polar covalent bond

  4. Pure covalent bond

  5. Metallic bond
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The type of bond between atoms of calcium in a crystal of calcium is Metallic bond.
Metallic solids are the crystalline solids formed by atoms of the same metallic element. The bonding electrons are delocalised over entire crystal lattice and can move freely from one end to other. These bonding electrons forms sea of electrons whereas metal ions form a kernel. Metallic bond is the electrostatic attractive force between positively charged metallic ions and negatively charged delocalised electrons.

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

Metallic bonding is explained by:

  1. electron sea model

  2. band model

  3. both A and B

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In contrast to electrons that participate in both ionic and covalent bonds, electrons that participate in metallic bonds delocalize, forming a sea of electrons around the positive nuclei of metals. The availability of "free" electrons contributes to metals being excellent conductors.

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

Which of the following bonds produces a solid that reflects light in the visible region and whose electrical conductivity decreases with temperature and has high melting point?

  1. Metallic bonding

  2. Ionic bonding

  3. Covalent bonding

  4. Van der Waals bonding
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Metals (metallic bonds) have these physical properties- 


1) Metals reflect the photons of the visible spectrum (light) falling on their surface, thus metals are often silver-white or greyish with the characteristic specular reflection of metallic lustre.

2) The electrical conductivity of metals decreases with a rise in temperature.
3) Metals have a high melting point.

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

A  4 : 1 mixture of helium and methane is contained in vessel at 10 bar pressure. Due to a hole in the vessel, the gas mixture leaks out. The composition of mixture effusing out initially is

  1. 8:1

  2. 8:5

  3. 1:8

  4. 5:8
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

According to Graham's Law of Effusion, the rate of effusion is proportional to the mole fraction of the gas and inversely proportional to the square root of its molar mass. For a 4:1 mixture of He (mass 4) and CH4 (mass 16), the ratio of effusion rates is (4/sqrt(4)) : (1/sqrt(16)) = 2 : 0.25 = 8:1.

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

Which of the following properties are because of presence of metallic bonding in metal atoms :

  1. Electrical conductivity

  2. Malleability

  3. Ductility

  4. All of the above

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Many of the characteristic properties of metals are attributable to the non-localized or free-electron character of the valence electrons. This condition, for example, is responsible for the high electrical conductivity of metals. The valence electrons are always free to move when an electrical field is applied. The presence of the mobile valence electrons, as well as the nondirectionality of the binding force between metal ions, account for the malleability and ductility of most metals. When a metal is shaped or drawn, it does not fracture, because the ions in its crystal structure are quite easily displaced with respect to one another. Moreover, the nonlocalized valence electrons act as a buffer between the ions of like charge and thereby prevent them from coming together and generating strong repulsive forces that can cause the crystal to fracture.
Hence option D is correct.