Scientists are studying how substance a and substance b react. when substance a and b are mixed, a substance different from a and b floats to the top of the solution. this is evidence that a(n) question 6 options: a. chemical change occurred. b. irreversible change occurred. c. endothermic change occurred. d. physical change occurred.

This is evidence that a. a chemical change occurred.

Substances A and B must have changed into the new substance with new properties. That’s a chemical change.

The reaction could be reversible (A + B ⇌ product) or irreversible (A + B → product). WE can’t tell just by looking at the reaction.

The question didn’t say whether heat was absorbed or evolved, so we don’t know if the reaction is endothermic or exothermic.

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explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.