“Chance” and “opportunity” both refer to a favorable time or circumstance. An “opportunity” is the right moment to take action toward a definite goal. It is a favorable or advantageous combination of circumstances. “Chance” implies luck or accident in the arrival of an opportunity, total absence of design or predictability. Examples: “Take advantage of this opportunity to improve your career.’ “If you ever have a chance to work in that department, grab it.”

Chance is more neutral, and opportunity is possibility to do something that benefits you. Chance can be used when you got less control on situation and more luck. Opportunity is used only when you are more or less in control of situation. So you take a chance that weather will be sunny, while you take opportunity to use your sun umbrella.