Int Science- Chemical change

• a chemical change, also known as a chemical reaction, involves the formation of new substances with different chemical properties. it results in a change in the composition and identity of the substances involved.
• when a substance undergoes a chemical change, its molecular composition is changed entirely. thus chemical change involves the formation of new substances
• a chemical change is a permanent change
• chemical change both physical and chemical properties of the the substances including its composition
• during a chemical reaction absorption and evolution of energy take place
• chemical change usally involves the production of energy
• a chemical change is always accompanied by one or more new substances
• chemical changes are irreversible
• any of the properties of matter that can be observed and measured only by performing a chemical change or chemical reaction
• chemical properties can not be determined by touching or viewing a sample; the structure of the sample must be altered for the chemical properties to become apparent.
• toxicity- the harmful effects of a substance on the body or mind
• flammability- the ability of a material to burn or catch fire easily
• radioactivity - the spontaneous decay of unstable nuclei, resulting in the emission of radiation
• reactivity - the tendency of an element to form compounds with other elements
• chemical properties are properties that can be measured by changing the chemical composition of a substance
• measured by changing the identity of a substance
• have a direct relationship to chemical bonds