Chemical Bonding and Solid State

Fill-in-the-blank flashcards covering key concepts, definitions, structures, and properties from the Unit IV lecture on Chemical Bonding and the Solid State.

The ancient Indian philosopher who first discussed the concept of the atom was __.

Acharya Kanad (Kashyap)

Kanad named the smallest indivisible particle of matter as __.

Parmanu

According to Kanad, parmanus combine to form larger particles called __.

Molecules

John Dalton proposed his atomic theory in the year __.

1808

Dalton stated that all atoms of a given element are __ in mass and properties.

identical

The electrons in the outermost shell that determine valency are called __.

valency electrons

An atom with 8 electrons in its outermost shell is said to have achieved the __ configuration.

octet

Transfer of electrons between atoms produces a(n) __ bond.

ionic (electrovalent)

Mutual sharing of electrons between atoms produces a __ bond.

covalent

One-sided sharing of an electron pair results in a __ bond.

coordinate (dative)

Delocalization of electrons through a metal lattice gives rise to a __ bond.

metallic bond

When hydrogen acts as a bridge between two electronegative atoms, a __ bond is formed.

hydrogen

Ionic bonding usually occurs between a __ and a non-metal.

metal

Covalent bonds are __ in nature, giving molecules definite shapes.

directional

Ionic compounds conduct electricity in the __ or aqueous state.

molten (fused) state

The force of attraction between neutral molecules due to temporary dipoles is called __ forces.

London dispersion

Dipole-dipole interactions are a type of __ forces.

Van der Waals

Hydrogen bonding is the __ of the Van der Waals forces.

strongest

Ionic bonds are __ (directional/non-directional).

non-directional

Covalent compounds generally have __ melting and boiling points compared to ionic compounds.

lower

Compounds with coordinate bonds have melting points than purely covalent compounds but than purely ionic compounds.

higher; lower

In a water molecule, oxygen forms __ single covalent bonds with hydrogen.

two

Sharing two pairs of electrons between two atoms forms a __ covalent bond.

double

The molecule N₂ contains a __ covalent bond.

triple

The simplest repeating unit of a crystal lattice is called the __.

unit cell

Particles are present only at the corners in a __ cubic unit cell.

simple (primitive)

A body-centred cubic cell contains __ atoms per unit cell.

2

A face-centred cubic cell contains __ atoms per unit cell.

4

The coordination number of an atom in a simple cubic lattice is __.

6

The coordination number in a BCC lattice is __.

8

The coordination number in FCC and HCP lattices is __.

12

Glass and rubber are examples of __ solids.

amorphous

Sodium chloride and diamond are examples of __ solids.

crystalline

Crystalline solids have __ melting points, while amorphous solids do not.

sharp

The axes and angles determining a unit cell are called the __ of the unit cell.

lattice parameters

Metals are malleable and ductile because metallic bonds are __ in nature.

non-directional

The bright shine of metals, known as metallic __, is due to delocalized electrons reflecting light.

luster

In metallic bonding, positive metal ions are surrounded by a sea of __ electrons.

delocalized (mobile)

Van der Waals forces are strongest in the __ state of matter.

solid

Matter exists in three common states: solid, liquid, and __.

gas

In gases, particles have __ intermolecular spaces.

large (huge)

Liquids and solids are also called __ phases because particles are close together.

condensed

The number of atoms in a molecule is called its __.

atomicity

Molecules containing three atoms, like CO₂, are termed __.

triatomic

In water, two molecules can associate via __ bonds to form clusters.

hydrogen

The crystal system with a = b = c and α = β = γ = 90° is called the __ system.

cubic

In the tetragonal system, the relationship of edges is __.

a = b ≠ c

London dispersion forces become stronger as the size and number of __ increase.

electrons (or molecular size)

In an ammonium ion, the bond between nitrogen and the extra hydrogen is a __ bond.

coordinate (dative)

The ability of a metal to conduct electricity is due to its __ electrons.

mobile (free)

The interatomic force that explains high melting points and hardness in ionic compounds is the __ attraction between ions.

electrostatic

When a substance like NaCl dissolves in water, the ion-dipole interaction increases its __.

solubility

The empirical measure of how many atoms each atom touches in a crystal is called its __ number.

coordination

In a hexagonal close-packed unit cell there are __ atoms per unit cell.

6

Most metals have crystal structures that are either BCC, FCC, or __.

HCP (hexagonal close packed)

Molecular solids are held together primarily by __ forces.

Van der Waals

The melting point of a metal is intermediate between those of and solids.

ionic; covalent

Rigid, directional bonds found in covalent solids make them generally __.

hard and incompressible