What is Mole?

• Mole is the unit of the Amount of Substance of any matter
• It is written as "mol" for short.
• Same number of moles of different substances contain same number of particles.
• Same number of moles of different substances possess different mass.
• The amount of particles present in 1 mole of any substance is 6.02x10 (which is also known as Avogadro's Number)

What is Avogadro's number

The fixed value of the amount of particles, atoms or molecules present in One Mole of any substance which was calculated by Amedeo Avogadro, an Italian Scientist who is most noted his contribution to the molecular physics and He was also the Count of Quaregna and Cerreto.

Avogadro's Number:

• The amount of atoms, molecules or particles present One Mole of any substance is called Avogadro's Number.
• The value of Avogadro's Number is: 6.02x10²³
• Avogadro's Number is denoted by or The symbol of Avogadro's Number is: N_A

Hydrolysis and Hydration

Q. What is Hydrolysis and Hydration?

Hydrolysis:

Hydrolysis is a process in which a compound breaks down into its substances due to reaction with water. It is a type of chemical reaction, hydrolysis involves adding a molecule of water which causes a bond between any other compound to break and then water replaces the molecule whose bond is broken. It can also be described as a type of single displacement or double displacement reaction which involves addition of water to decompose a specific compound.

Hydration:

Hydration is a process used to add water in to a compound or substrate in order to modify it. It is also a type of chemical reaction which involves the use of water to change a chemical or to modify it. Hydration can also be described as a type of addition reaction as this process is used to add water molecule into a compound.

Difference between Hydrolysis and Hydration:

Hydrolysis is used to add water into a compound in order to remove a substance and replace it with water whereas Hydration is used only to add water into a compound, it does not involve replacing or removing any mole from the compound.

Chemical Reaction

Q. What is a Chemical Reaction?

A chemical reaction occurs when two or more molecules interact with each other. They form bonds and create a new molecule.

In a chemical reaction, the molecules that interact with each other are called reactants and the molecules produced by the reaction are called products. During a chemical reaction, no new atoms are created or destroyed. A reaction could include atoms, ions, compounds or molecules of a single element. The reactants contact each other, bonds between the atoms are destroyed and they rearrange to form new bonds and as a result products are created.

Element, Compound and Mixture

Q. What is an Element?

Any individual type of atom that is used to make a material is known as element. A single atom of any material for example an atom of Hydrogen is called as element.

For example, if we look at the periodic table it says: Periodic Table of Elements and there you can see the first element is H (Hydrogen) which shows the mass and atomic number of a single atom of hydrogen.

There fore, we can say that

a single atom of any material is known as element.

Q. What is Compound?

Two or more elements chemically joined together makes a compound. When we take two different elements and chemically combine them that makes a new element that is known as Compound.

Newton's Law of Universal Gravitation

Q. State and explain Newton's Law of Universal Gravitation:-

Introduction:

In 1687, Sir Isaac Newton stated the Law of Universal Gravitation between two bodies.

Statement:

It states that, Any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of distance between them.

Application to the Principle to arrange an Extra Class:-

To,

The Principle,
Name of School/Institution,
Addres,
Date: xx.xx.xxxx

Respected Sir,

With all due respect, I state that I am the student of class X. I am monitor of the class. Our annual examinations are near and our class is very weak in English and Maths that is also evident by the half yearly examination. Our English teacher was regularly on leave because of his ill health and the Math teacher was very busy in his thesis.

Therefore, I request you on behalf of my whole class to arrange an extra class for these subjects as soon as possible. We will be very thankful to you for this act of kindness.

Yours obediently,
XYZ

Paragraph on: The School Peon

The person who sits outside the Principle's office or outside the school gate is the school peon. People think that a peon is not a important person but the Principle very well knows how important his services are for the school. We don't know how uppercase his services are for the school.

Letter to Younger Brother advising him to take part in games:-

Examination Hall

Address
Date: xx.xx.xxxx

Dear brother,
Greetings!

I am fine with the grace of Almighty Allah and I hope you are doing good as well. It is always advisable to make the best use of student life, as this part of life makes the character of our personality. However, this does not mean that you study day and night and forget about your health. I have been told that you do not play games as you are shy of doing so. I therefore advice you to take active part in games because games are also a necessary part of life. Games help us to stay fit and shape our body. You should try to overcome your shyness and participate in sports and games. As an elder brother I advice you to take part in games as games make us healthy, wealthy and wise as the adage goes health is wealth.

There fore, always try to take active part in sports and divide your time in study and games. I am sure you will act up on my advice.

Your affectionately
XYZ

Short Paragraph on Quaid-e-Azam Muhammad Ali Jinnah:-

Quiad-e-Azam Muhammad Ali Jinnah was the founder of our beloved country Pakistan. He was born on 25th December, 1876 in Karachi. His father name was Jinnah Poonja. He received his early education from Karachi then he went to England and took his Barrister's degree from Linchon's Inn.

Matter & its States

Q. What is Matter and how many states of matter?

All the material that is around us is made up of matter, Matter itself is made up of tiny tiny little building blocks called atoms.

Definition:

Matter is anything that occupies space and has mass.

Write a Short Paragraph on Railway Journey:-

During the last vacations, my favorite teacher Sir Ghulam Asghar Bhutto asked to take me and my friends to Lahore and spend a few days there. We were asked to arrive at the station at seven o'clock

On the next morning we arrived at Hyderabad station at about seven o'clock and boarded the Lahore Express at about eight o'clock and the train left in time. We found that the compartment was full of passengers and piles of luggage. Somehow I managed to sit by the side of a window.