1. Atom is the smallest part of an element while molecules are made of two or More atoms
2. Atoms can't be separated into subatomic particles by chemical reaction whereas molecules can be separated into atoms by chemical reaction.
3. Hydrogen , oxygen , nitrogen are some examples of atoms while H^2O( water), NO^2 are some examples of molecules.
4. Atoms have no bonding whereas molecules have intermolecular forces intra-molecular forces.
5. Atoms may or may not have properties of matter whereas molecules have properties of matter.

Atoms:
- Atoms are the basic building blocks of matter.
- They are the smallest unit of an element that retains its chemical properties.
- Atoms consist of a central nucleus that contains positively charged protons and uncharged neutrons. Surrounding the nucleus are negatively charged electrons.
- Atoms are indivisible and cannot be broken down further without losing their chemical properties.
- Each element is made up of a unique type of atom.

Molecules:
- Molecules are formed when two or more atoms chemically combine.
- They are the smallest unit of a compound that retains its chemical properties.
- Molecules can be made up of atoms of the same element (diatomic molecules) or atoms of different elements (polyatomic molecules).
- In a molecule, atoms are held together by chemical bonds, which can be covalent or ionic.
- Molecules have a distinct set of properties that are different from the properties of individual atoms.
- The properties of a molecule depend on the types and arrangement of atoms within it.

Relationship between Atoms and Molecules:
- Atoms are the building blocks of molecules.
- Molecules are composed of atoms that are chemically bonded together.
- When atoms combine, they form molecules with different properties and characteristics.
- The number and types of atoms present in a molecule determine its chemical formula and properties.
- Molecules can be composed of atoms of the same element (e.g., O2, N2) or different elements (e.g., H2O, CO2).

NCERT Solutions - Atoms And Molecules:
- NCERT Solutions for the chapter "Atoms and Molecules" provide answers to the questions and exercises given in the NCERT textbook for Class 9.
- These solutions help students understand the concepts of atoms, molecules, chemical formulas, and equations.
- The solutions provide step-by-step explanations, diagrams, and examples to facilitate better understanding.
- They cover topics such as the law of conservation of mass, atoms and molecules, writing chemical formulas, balancing chemical equations, and calculating molecular masses.
- NCERT Solutions help students prepare for exams by providing practice questions and solutions for self-assessment.
- They are an important resource for students to clarify their doubts and strengthen their understanding of the subject.
- NCERT Solutions can be accessed through various online platforms, including EduRev, which provides free and reliable study materials for students.