I think I have done a question like this before and i'm pretty sure your answer would be the 2nd one 1s22s22p4. I'm not 100% sure but try it at least.
The answer would be: K
Kalium or Potassium is one of the metal that located in the first column of the periodic table. It was a strong base with one valence. If react with water it would have an equation:
2K + 2H2O = 2KOH + H2
The kalium hydroxide will form ion if put on the aqueous state. It will become K+ and OH-, thus increasing the water pH.
