Skip to main content

Atomic number, Mass number and Atomic species

 Atomic number, Mass number and Atomic species

Atomic number or Nuclear charge 

(i) The number of protons present in the nucleus of the atom is called atomic number (Z). 
(ii) It was determined by Moseley as, 

V1/2 =a(z-b)

Where, v=X -  ray’s frequency

 Z= atomic number of the metal a & b are constant. 
(iii) Atomic number = Number of positive charge on nucleus = Number of protons in nucleus = Number of electrons in nutral atom.
 (iv) Two different elements can never have identical atomic number.

 Mass number 

Mass number (A) = Number of protons or Atomic number (Z) + Number of neutrons or Number of neutrons = A – Z .
 (i) Since mass of a proton or a neutron is not a whole number (on atomic weight scale), weight is not necessarily a whole number.
 (ii) The atom of an element X having mass number (A) and atomic number (Z) may be represented by a symbol, ZXA

Different types of atomic species

Isotopes

Given by Soddy

1.They are the atoms of a given element  which have the same Atomic number (Z) but different Mass number (A).

2.They have same number of protons and same number of electrons but  different number of neutrons.

3. They have same electronic confriguration , same chemical properties and same position in the periodic table but different physical properties. 

examples: 


 Isobars

Given by Aston 
1.They are the atoms of different elements which have the same Mass number (A) but different Atomic number(Z).
2.They have different number of electron , protons and neutrons but sum of number of protons and neutrons i.e. number of neucleons remains same .
3. They have different electronic configuration , chemical properties and the position in the periodic table. 
examples 

 Isotones

1.They are the atoms of different elements which have the same number of neutrons but different atomic number, mass number , number of protons and number of electrons.

2. They have the different electronic configuration, physical properties , chemical properties and position in the periodic table. 

examples 

Isodiaphers 

They are the atoms of different elements which have the same difference of the number of Neutrons and protons. 
examples 

Isoelectronic species 

They are the atoms of given element which have the same number of electrons and electronic configuration but different atomic numbet and mass number. 
examples 

Isosters 

they are the molecules which have the same number of atoms , number of electrons and physical properties and chemical properties. 
examples 



Labels:

Comments

Post a Comment

Popular posts from this blog

Chemistry 101: A Beginner's Guide to Understanding the World Around Us

Chemistry 101: A Beginner's Guide to Understanding the World Around Us Chemistry  What is Chemistry ? Chemistry is the study of matter and its properties, composition, and interactions with other substances. It is a fundamental science that encompasses a wide range of topics, from the behavior of atoms and molecules to the reactions that occur in living organisms. Chemistry is the foundation of modern technology and plays a critical role in fields such as medicine, engineering, and materials science. At its core, chemistry is concerned with understanding the structure and behavior of matter at the atomic and molecular level. Chemists study the properties of elements, the structure of molecules, and the forces that govern chemical reactions. They also investigate the behavior of matter under different conditions, such as temperature, pressure, and concentration. One of the key aspects of chemistry is the concept of the chemical bond, which is the force that holds atoms together in m...
1 comment
Read more

States of Matter: gaseous states, gas laws, ideal gas equation

  Introduction  Matter is made up of atoms or molecules. The arrangement of these molecules determines the state of matter. There are three recognised state of matter : Solid, Liquid and Gas. Matter can change between states when the temperature or pressure is changed. State changes of matter are physical rather than chemical. Difference between states of matter  GASEOUS STATE  Important properties of gases :  ( i ) Mass : Mass in gm = Moles × Molecular mass.  (i i) Volume : Volume of the gas is the volume of container in which they are filled in.  (iii) Temperature : Temperature of a gas is the measure of kinetic energy of gas.                      Kinetic energy ∝ Temperature ( i v) Pressure : Pressure of gas is defined as the force exerted by the gas on the walls of its container. It is often assumed that pressure is isotropic, i.e. it is the same in all the three directions.  Pressure = F...
Post a Comment
Read more

A Step-by-Step Guide to JEE Main 2023 Session 2 Registration Process

A Step-by-Step Guide to JEE Main 2023 Session 2 Registration Process JEE Main 2023 Session 2 : Registration Link Active at jeemain.nta.nic.in; How to Apply, Direct Link The National Testing Agency (NTA) has begun the Joint Entrance Examination (JEE) Main 2023 session 2 registration. JEE Mains second attempt registration link is active now on the official website jeemain.nta.nic.in . Aspiring candidates will be able to register for the JEE Main 2023 session 2 exams through the login window. Apply for online registration  Click here   NTA will conduct the JEE Main 2023 session 2 examinations on April 6, 8, 10, 11, and 12. "The dates of advance intimation of examination city, downloading of admit cards, and declaration of result will be displayed on JEE (Main) portal in due course," NTA said in an official notice earlier. The official notice  You can download the official notice you this  Click here   How to fill JEE Main 2023 Application Fo...
Post a Comment
Read more