When elements combine or join together new substances are formed. These substances are called compounds. This is shown in the diagram below There are millions of different compounds and all of them ...

Try these interactive flashcards based on GCSE chemistry past papers. By working your way through the flashcards created by experts, you can prepare for your chemistry exams and make your revision ...

Lewis structures, also called electron-dot structures or electron-dot diagrams, are diagrams that show the bonding between atoms of a molecule, and the lone pairs of electrons that may exist in the ...

Students use the terms isotope, atomic number, mass number, and atomic mass. Atomic Theory: Structure of the Atom: Students use the terms isotope, atomic number, mass number, and atomic mass to ...

JEE Main 2020 & NEET 2020: Get important MCQs (with answers) from NCERT book of CBSE Class 11 Chemistry (Chapter 2 - Structure of Atom). These important MCQs are based on topics & concepts from which ...

The Bohr model, introduced by Danish physicist Niels Bohr in 1913, was a key step on the journey to understand atoms. Ancient Greek thinkers already believed that matter was composed of tiny basic ...