let me just copy and paste exactly helium we want to put Helium in the S block so we want to put Helium right there the reason why, just in case you are curios of why Helium is put there in the periodic table is because it has very similar properties to the other elements in this columns or this group each column is called a group and we'll talk about valence electrons and why that leads to different properties but for electron configuration purposes we can put it in the S block and that's not too hard to remember beacuse it's just one element and it kind of makes sense,1s1, 1s2, etc.
ผมจะ copy แล้วแปะฮีเลียม เราต้องการเอาฮีเลียม..ไปไว้ใน S block ดังนั้น เราจะเอาฮีเลียมไว้ตรงนี้