1.2 Features of chemical changes 1.Qualitative change(化学变化是质变) *Formation of new substances *Formation of new chemical bonds with concomitant cleavage of old ones H2+02→H20 化学变化 242,6Cm(锔)+42He→245gCf(锎)+'n physical reaction 1.2 Features of chemical changes 1. Qualitative change (化学变化是质变 ) 242 96Cm( 锔)+ 4 2He → 24598Cf（锎） + 1 0n physical reaction H 2+O 2 → H 2O 化学变化 ☆ Formation of new substances ☆ Formation of new chemical bonds with concomitant cleavage of old ones