Question

Hi, I need to double check my homework answer, need help with this. My answer is in bold:

A) Which solids may exist in the solid state at room temperature?

Ionic Solids, Molecular Solids, Metallic Solids, or Covalent Network Solids

B) Which types of solids conduct electricity as pure solids (not aqueous)?

Molecular Solids, Ionic Solids, Metallic Solids, or None of these

C) What does the flat part of heating curves indicate?

Gaseous states, Liquid states, Solid States, Phase transitions

D) Boiling occurs in a liquid when:

Its vapor pressure rises until it's equal to external pressure.

Its vapor pressure drops below external pressure.

The rate of evaporation equals the rate of condensation.

Over half the particles are in the gas phase.

Answer 1

Q.A) Metalic solids do exist at room temperature

( due to strong inter molecular  forceof attraction metal exist high melting point ,so metalic solid do exist at room temperature.)

And in case of covalent solid and ionic solid we know covalent force is stronger so covalent solid has high probability.

The attractive force between units are sufficientlystrong to hold them in position in a lattice despite the vibrational energies of the units. Large covalent molecules and ionic compound are typically solids at room temperature.

A molecular solid is composed of molecules held together by van der Waals forces .Its properties are dictated by the weak nature of these intermolecular force.Molecularsolids are soft ,often volatile,have low melting temperature,and are electrical insulators.

Q.D The moleculas solich is composed of molecules held together by van- der Waals forees, so free electron orion to conduet electricity. This is why molecular solids are electrical insulators there was no Ionic solida Ionie solid are are conduct electricity in molten state not in solid state. In solid state ions held together by strong electro statie attraction forces and not free to move about within the solid so we can say jonie solids electrical insulators. metalic solids : Metalic solids have the high electrical conductivity come from the fact that one or more valence electron is relatively free to travel throughout the solid material (mecodding to free electron theory).

Q.C) A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. The plateaus on the curve mark the phase changes. The temperature remains constant during these phase transitions.

Q.D)  The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.

The normal boiling point (also called the atmospheric boiling point or the atmospheric pressure boiling point) of a liquid is the special case in which the vapor pressure of the liquid equals the defined atmospheric pressure at sea level, one atmosphere. At that temperature, the vapor pressure of the liquid becomes sufficient to overcome atmospheric pressure and allow bubbles of vapor to form inside the bulk of the liquid. The standard boiling point has been defined by IUPAC since 1982 as the temperature at which boiling occurs under a pressure of one bar.