Which of the Following Statement 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 18 Vertical Columns Known as Groups. (D) It Has 7 Horizontal Rows Known as Groups. - Science
Which of the following statement 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 18 vertical columns known as groups. (d) It has 7 horizontal rows known as groups.