Question

Which of the following statements about the modern periodic table is correct

(a)it has 18 horizontal rows known as periods
(b)it has 7 vertical columns known as periods
(c)it has 3 vertical columns knowns as periods
(d)it has 7 horizontal rows known as groups ​

Answer 1

Answer:

I think the right answer is option d

Answer 2

Answer:

b) 7vertical columns known as periods. is your answer