Explanation:

First three periods are Short periods.

• In the periodic table of elements, there are seven horizontal rows of elements called periods. The vertical columns of elements are called groups, or families. (Period number 1, 2 and 3 contain 2, 8 and 8 elements respectively. Other periods contain more than 8 elements. Hence, the first three periods are called as short periods. So, total of 3 short periods are there in Mendeleev periodic table. Hence option 2nd is correct.