Question

$\sf \red {1. Explain \: Melting \: (Fusion)}$
$\sf \red {2. Explain \: Boiling}\ \textless \ br /\ \textgreater$
$\sf \red {3. Explain \: effects \: of \: temperature \: on \: molecular \: motion. \: with \: a \: diagram.}$
$\sf \red {4. Explain \: Sublimation}$
$\sf \red {5.Explain \: Effect \: of \: pressure \: on \: gases}$
Explain clearly .
Class 9 . Science .​

Answer 1

1) Explain melting (fusion)

→ Melting, or fusion, is a physical process that results in the phase transition of a substance from a solid to a liquid. This occurs when the internal energy of the solid increases, typically by the application of heat or pressure, which increases the substance's temperature to the melting point.

2) Explain boiling

→ Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

3) Explain effects of temperature on molecular with a diagram.

→ If the temperature is increased, the average speed and kinetic energy of the gas molecules increase. If the volume is held constant, the increased speed of the gas molecules results in more frequent and more forceful collisions with the walls of the container, therefore increasing the pressure.(diagram in imager refer it )

4) Explain sublimation.

→ Sublimation is the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. For those of us interested in the water cycle, sublimation is most often used to describe the process of snow and ice changing into water vapor in the air without first melting into water.

5) Explain effect of pressure on gases.

→ Changing the pressure of an equilibrium system in which gases are involved is also a stress to the system. A change in the pressure on a liquid or a solid has a negligible effect.

I HOPE ITS HELP YOU

Answer 2

${\large{\pmb{\sf{\underline{RequirEd \; Solution...}}}}}$

Question 1. What is melting? (fusion)

Answer 1. The process of melting is known as fusion. Melting is also defined as the change of solid state of particles into the liquid state.

Question 2. What is boiling?

Answer 2. Boiling is the bulk phenomenon. Particles from the bulk of the liquid gains enough energy to be chaged into the vapour or gaseous state.

Extra about these topic:

Two properties of a substance to check that substance purity is given below:

• 1st property = Melting point.
• 2nd property = Boiling point.

Melting point = The temperature at which solid and the liquid forms of the substance exist at equilibrium or both forms have same vapour pressure is called melting point.

Boiling point = The temperature at which the vapour pressure of the liquid is equal to atmospheric pressure is called boiling point.

• Boiling point for Water is 373 K

• Boiling point for Ethanol is 349 K

• Boiling point for Chlroform is 334 K

• Boiling point for Acetone is 329 K

$\begin{gathered}\begin{gathered}\boxed{\begin {array}{c|c|c|c}\sf Temperature \:Scale &\sf Ice\:point &\sf Steam \;point &\sf No\;of\:division\:on\:Fundamental\;interval \\ \frac {\qquad\qquad\qquad}{} &\frac{\qquad\qquad\qquad}{} & \frac {\qquad\qquad\qquad}{} & \frac {\qquad\qquad\qquad\qquad\qquad\qquad}{} \\ \sf Celsius\;scale & \sf0^\circ C &\sf100^\circ C &\sf 100\\&&&\\ \sf Fahrenheit\:scale & \sf32^\circ F &\sf 212^\circ F &\sf180 \\&&&\\ \sf Kelvin\;scale &\sf273K &\sf373K & \sf100\\&&&\\ \sf Reaumer \:scale &\sf0^\circ R &\sf80^\circ R &\sf80\end {array}}\end{gathered}\end{gathered}$

Important regards these topic:

Kelvin is the melting point of ice. Kelvin is the SI unit of temperature. 0°C is equal to 273.16 K. But we take it as 273 in rounding figure.

Question 3. Explain effect of temperature on molecular with the help of diagram.

Answer 3. Kindly see diagram from the above attachment. Now tell what you observe? We are observing that these is a change in the molecule after heating. Remeber the process of expansion? Ya right! This chance in molecules is just because of heating. Whenever heat then molecule looses.

Question 4. Explain sublimation.

Answer 4. Sublimation is the change of gaseous state directly to solid state without going through liquid state.

Question 5. Explain effect of pressure on gases.

Answer 5.

• When pressure increases then

When pressure increases them the molecules have less space in which they can move. Reaction produce few gas molecules.

• When pressure decreases then

Reaction produce more gas molecules.