S10 5: Changes in Matter, Reaction Types

• Physical changes = molecules are unchanged, and still possesses the same properties (ex. water turns to ice)
• Chemical changes = change in bonds between atoms, formation of new substances + new permanent properties, colour, odour, state
• Synthesis reactions involve the combination of two or more substances to form a new compound
• Decomposition reactions involve the breakdown of a compound into simpler substances
• Single replacement reactions occur when one element replaces another element in a compound. element + compound = element + compound
• Double replacement reactions involve the exchange of ions between two ionic compounds to form two new compounds metals never pair with each other
• Combustion reactions involve the reaction of a fuel + oxygen to get water + oxygen
• Kinetic Molecular Theory: particles are in continuous motion and collide with each other & objects in their path. Collision = new products