Question

which of the following statements is true about the elements labeled a and b? a - element a is a non - metal, and element b is a metal. b - element a forms a 2 - ion, and element b forms a 1+ ion. c - element a is a solid, and element b is a gas at room temperature. d - element a has two valence electrons, and element b has one valence electron.

Explanation:

Elements form ions based on valence - electron loss or gain. A 2 - ion suggests gaining 2 electrons (common for elements with 6 valence electrons), and a 1+ ion suggests losing 1 electron (common for elements with 1 valence electron).

Answer:

B - Element A forms a 2 - ion, and element B forms a 1+ ion.