Chemical Reactions and Atomic Structure
Think of atoms as the ultimate building blocks - they're literally what everything is made of. Each element on the periodic table gets its own symbol, like a chemical shorthand that scientists use worldwide.
Compounds form when two or more different atoms decide to chemically bond together, creating something completely new. During chemical reactions, atoms simply rearrange themselves - they never disappear or magically appear, which is why you need to balance equations.
Your understanding of atomic structure has evolved thanks to brilliant scientists over time. JJ Thompson started with the "plum pudding model," but Ernest Rutherford discovered that atoms actually have a tiny, dense nucleus at their centre. Neils Bohr then figured out that electrons orbit in specific shells, whilst James Chadwick identified neutrons hiding in the nucleus alongside protons.
Quick Tip: Remember that the atomic number tells you how many protons an element has, whilst the mass number is protons plus neutrons. Isotopes are just atoms with extra or fewer neutrons - same element, different weight!
The periodic table isn't random - it's organised by atomic number, and elements in the same group behave similarly because they have the same number of outer shell electrons. Metals (left side) love giving away electrons, whilst non-metals (right side) prefer collecting them.
