Question

which two elements only need two valence electrons to be happy? 15/15 lithium and neon copper and iron californium and berkelium hydrogen and helium paul k**

Explanation:

To determine the two elements that only need two valence electrons to be "happy" (achieve a stable electron configuration), we analyze each option:

• Lithium and Neon: Lithium (Li) has 1 valence electron and needs to lose 1 (to have a stable configuration like helium, 2 electrons in the first shell), but Neon (Ne) is a noble gas with 8 valence electrons (stable octet), so this is incorrect.
• Copper and Iron: These are transition metals with more complex electron configurations and do not follow the "two valence electrons for stability" rule; they typically form ions with various charges, so this is incorrect.
• Californium and Berkelium: These are actinide elements with complex electron configurations and do not follow the simple "two valence electrons for stability" pattern, so this is incorrect.
• Hydrogen and Helium: Hydrogen (H) has 1 valence electron and can achieve stability by either gaining 1 electron (to have 2, like helium) or forming a bond. Helium (He) is a noble gas with 2 valence electrons (a stable duet in its only shell). So both only need two valence electrons (or a configuration equivalent to two) to be stable.

Answer:

Hydrogen and Helium