Question

Element X is in group 2, and element Y in group 7, of the periodic table. Which ions will be present in the compound formed when X and Y react together? A. X+ and Y- B. X 2+ and Y- C. X+ and Y2- D. X2- and Y+

Answer 1

B. X 2+ and Y -

Step-by-step explanation:

Elements in group 2A of the periodic table lose two electrons to achieve a complete valence shell, while elements in group 7A (also known as group 17B) gain one electron to achieve a complete valence shell. When atoms lose electrons, they have a positive charge, because there are more protons than electrons. When atoms gain electrons, they have a negative charge because there are more electrons than protons. Losing two electrons gives element X a charge of 2+, and gaining one electron gives element Y a charge of 1-.

The correct answer is B. X 2+ and Y -.