Answer:
The element with electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5 is manganese (25Mn).
Explanation:
Step 1: Data given
The element with electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5
has 25 electrons.
This element has 2 electrons on the first shell, 8 electrons on the second shell, 13 electrons on the third shell and 2 electrons on the outer shell (valence electrons).
This means this element is part of group VII.
The element with 25 electrons, we can find on the periodic table, with atomic number 25.
The element with electron configuration 1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^5 is manganese (25Mn).
First, you write the balanced equation for the reaction
2HCl + Mg(OH)2 ----->MgCl2 + 2H2O
Next, find the number of moles of Magnesium Hydroxide
Number of moles of Mg(OH)2 =
mass / Mr = 3.33 / 24 +2(1+16)
=0.0574 mol
Find the mole ratio between HCl and Mg(OH)2 which is 1:2
Number of moles of HCl = 0.0574 x 2 = 0.1148 mol
Mass of HCl = Mr x no. of moles
=0.1148 x (1+35.5)
=4.19 g
I would go with C hope this helps
