{"choices":[{"subContentId":"179c3376-9cbb-4d2f-8f6d-4652a0ed439e","question":"

When elemental iron corrodes it combines with oxygen in the air to ultimately form red brown iron(III) oxide called rust.<\/p>\n\n

If a shiny iron nail with an initial mass of 23.2 g is weighed after being coated in a layer of rust, would you expect the mass to have increased, decreased, or remained the same?<\/p>\n","answers":["

Increased as it would have combined with oxygen in the air thus increasing the amount of matter and therefore the mass.<\/p>\n","

Decreased as it would have combined with oxygen in the air thus decreasing the amount of matter and therefore the mass.<\/p>\n","

There will be no change.<\/p>\n"]},{"subContentId":"7ecadb33-4307-4e35-951f-6d577e03c954","question":"

When elemental iron corrodes it combines with oxygen in the air to ultimately form red brown iron(III) oxide called rust.<\/p>\n\n

If the mass of the iron nail increased from its initial mass of 23.3 g to 24.1 g, what mass of oxygen combined with the iron?<\/p>\n","answers":["

0.9 g<\/p>\n","

0.8 g<\/p>\n","

0.7 g<\/p>\n","

None of the above<\/p>\n"]}],"overallFeedback":[{"from":0,"to":100}],"behaviour":{"autoContinue":true,"timeoutCorrect":2000,"timeoutWrong":3000,"soundEffectsEnabled":true,"enableRetry":true,"enableSolutionsButton":true,"passPercentage":100},"l10n":{"nextButtonLabel":"Next question","showSolutionButtonLabel":"Show solution","retryButtonLabel":"Retry","solutionViewTitle":"Solution list","correctText":"Correct!","incorrectText":"Incorrect!","muteButtonLabel":"Mute feedback sound","closeButtonLabel":"Close","slideOfTotal":"Slide :num of :total","scoreBarLabel":"You got :num out of :total points","solutionListQuestionNumber":"Question :num","a11yShowSolution":"Show the solution. The task will be marked with its correct solution.","a11yRetry":"Retry the task. Reset all responses and start the task over again."}}

Interactive Exercise 1.4

Daryl Aranha