(1) The element with an electron configuration of 1s22s22p63s23p64s23d6 is in group ? and ? period .

Question

(2) The element with an electron configuration of 1s²2s²2p¹ is in group ? and ? period  .

Answer 1

26 electrons = Fe

Also, looking at the configuration, you see it is 4s2 3d6 (or 3d6 4s2) so looking at 3d6 you see it is Fe

For 1s2 2s2 2p1, there are 5 electrons so it is B (boron) in group 13(3A) and period 2. You can also tell this by the valence shell 2s2 2p1 indicating period 2 and 3 valence electrons putting it in group 13(3A).

Answer 2

Alexandria

Just add up the electrons. the number of protons must be the same as the element is electrically neutral. Then number of protons = atomic number, so you can find it in the periodic table.

In 1 , 1s2 2s2 2p6 3s2 3p6 4s2 3d6 so number of electrons = 2 + 2 + 6 + 2 + 6 + 2 + 6 = 4.2 + 3.6 = 24

So 24 protons and the atomic number is 24.

Same idea for (b)

Mike