In which highlighted section of the periodic table shown above are the elements that have 2 valence electrons? How do you know? Can someone help plsss

For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with ph. if the solubility does change, pick the ph at which you'd expect the highest solubility. you'll find ksp data in the aleks data tab. compounds does solubility change with ph

Which of the following is most likely true about water in chemical systems? a) water dissolves nonpolar ionic compounds. b) water dissociates ionic compounds. c) water dissociates covalent molecules. d) water dissolves nonpolar covalent substances.

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!