Question

How many periods are there in the modern periodic table of elements?​

Answer 1

Seven periods

Step-by-step explanation:

There are seven periods in the periodic table, with each one beginning at the far left. A new period begins when a new principal energy level begins filling with electrons. Period 1 has only two elements (hydrogen and helium), while periods 2 and 3 have 8 elements.

Answer 2

There are seven periods in the modern periodic table.