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Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Imagine that twenty i.u.’s of enzyme z were catalyzing the above reaction for one minute, under vmaxconditions, in a 3.00 ml assay volume. the assay is buffered with 20 mm phosphate buffer, ph 7.60. what will the ph be at the end of that one minute?

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude