Can anyone pls answert

What type of solution is formed if 10 g of kclo3 are dissolved in 100g of water at 30

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!