Check all the boxes that are true statements. 1. The removal of the second electron from a magnesium atom requires less energy than the removal of the first electron.2. A sulfur atom is larger than a sulfide ion (S²⁻).3. H⁺ is larger than H.4. The electron configuration for Cu is 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰.5. The second ionization energy for a calcium atom is less than the second ionization energy for a potassium atom.

Answer:Energy required to remove the most loosely bounded electron from an isolated gaseous atom is called as ionization energy.2nd ionization energy of Mg is more than 1st ionization because removal of first electron causes an increase in the value of on the remaining 2s electron, therefore, in order to free it, more energy needs to be provided, so that attraction force between 2s electron and nucleus can be overcome and 2nd electron can released.Yes, 2nd ionization energy of Ca is less than K because after the removal of first electron, K acquires a noble gas configuration like a Ar, so, when we take out one more electron from K, its octet is disrupted and that demands more energy while in Ca, removal of 2nd electron provides it an electronic configuration like Ar, that's why it demands less energy.Whenever we add an electron into a neutral atom, it decreases the value of zeff and due to that size of the specie increases and whenever we remove an electron from a neutral atom, it increases the value of zeff and due to that size of the specie decreases. For this reason, size order is:Electronic configuration of copper is and that happens because in this case, 3d subshell is fulfilled and 4s is half filled and it is well known that fulfilled and half filled subenergy levels are more stable.