Text go out of the column in 'Bootstap'

When I copy the text in one line into the code and check the page I find out that the text is getting out of the column in bootstrap, is code is like 

<div ><div ></div><div ><h2>Helllllllllllllllllllllllllooooooooooooooooooolllllll</h2></div><div ></div></div>

How can I keep it on the page, I tried flex-wrap: wrap; but I still facing the same issue,

Thanks in advance