Isaiah has been taught not to get involved in drugs. However, he puts that aside and tries marijuana after he sees his older brother using it without getting in trouble. What best explains Isaiah's behavior?

This would be a simple situation of a brother following his older sibling.

Explanation:

I've seen this before.

Even though Isaiah has been taught by his teachers and/or parents not to use drugs, he will try it if he sees his brother trying it without the consequences he has heard of from his teachers and/or parents.

Unless the older sibling has done anything wrong in the younger sibling's eyes, the younger sibling will always look up to his older brother/sister. Even if the younger brother has been taught over and over again not to do something because of the horrid consequences that come with it, he will do it if he sees his brother doing the same without the consequences specified.

In other words : If the older brother hasn't been caught by anyone for using drugs, the younger brother will follow suit, or at least try to do the same.

Hope this helps.

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals