Answer
a) The elements with this electron configuration ending have three valence electrons and belong to the p block. Therefore, these elements are in group 3A. The elements are B (boron), Al (aluminum), Ga (gallium), In (Indium), and Tl (thallium).
b) The elements with this electron configuration ending have 7 valence electrons and belong to the p block. These elements are found in group 7A, commonly known as the halogens. The elements are F (fluorine), Cl (chlorine), Br (bromine), I (iodine), At (astatine).
c) In this case we do not look at the higher energy shell (valence electrons). We know that these elements are in the d block, and are therefore transition metals. All we need to do is to look at the number of electrons in the d orbitals in order to determine the group these electrons are in. With two electrons in the d orbitals, we deduce that the elements belong to the group 4B. The elements are Ti (titanium), Zr (zirconium), Hf (hafnium), and Rf (rutherfordium).
Work Step by Step
a) The elements with this electron configuration ending have three valence electrons and belong to the p block. Therefore, these elements are in group 3A. The elements are B (boron), Al (aluminum), Ga (gallium), In (Indium), and Tl (thallium).
b) The elements with this electron configuration ending have 7 valence electrons and belong to the p block. These elements are found in group 7A, commonly known as the halogens. The elements are F (fluorine), Cl (chlorine), Br (bromine), I (iodine), At (astatine).
c) In this case we do not look at the higher energy shell (valence electrons). We know that these elements are in the d block, and are therefore transition metals. All we need to do is to look at the number of electrons in the d orbitals in order to determine the group these electrons are in. With two electrons in the d orbitals, we deduce that the elements belong to the group 4B. The elements are Ti (titanium), Zr (zirconium), Hf (hafnium), and Rf (rutherfordium).
