how is the periodic law demonstrated within the groups of the periodic table?
also I need help writing the noble gas notation for the electron configuration of each of the following elements and indicate the period in which they belong
a Li-
b O-
c Cu-
d Br -
e Sn-
The periodic law is demonstrated within the groups of the periodic table by the similarity in the chemical properties of elements in the same group. Elements in the same group have the same number of valence electrons, which are the electrons in the outermost energy level or shell of an atom. These valence electrons determine an element's chemical behavior and reactivity.
To write the noble gas notation for the electron configuration of each element and indicate their respective periods, we need to identify the noble gas that comes before the element in the periodic table. The noble gases, also known as Group 18 elements, have stable electron configurations. We can use noble gases as shorthand to represent the electron configuration of elements that follow them.
a) Li- (Lithium): Lithium belongs to Period 2. Let's write its noble gas notation. The noble gas preceding lithium in the periodic table is helium (He), with an electron configuration of 1s2. The electron configuration of lithium (Li) is 1s2 2s1. Since we have Li-, it means that one electron has been removed, resulting in: 1s2 2s0. Thus, the noble gas notation for Li- is [He].
b) O- (Oxygen): Oxygen belongs to Period 2. The noble gas preceding oxygen is neon (Ne) with an electron configuration of 1s2 2s2 2p6. The electron configuration of oxygen (O) is 1s2 2s2 2p4. Since we have O-, it means that one electron has been added, resulting in: 1s2 2s2 2p5. Thus, the noble gas notation for O- is [Ne] 2p5.
c) Cu- (Copper): Copper belongs to Period 4. The noble gas preceding copper is argon (Ar) with an electron configuration of 1s2 2s2 2p6 3s2 3p6. The electron configuration of copper (Cu) is 1s2 2s2 2p6 3s2 3p6 4s2 3d9. Since we have Cu-, it means that one electron has been removed, resulting in: 1s2 2s2 2p6 3s2 3p6 4s2 3d10. Thus, the noble gas notation for Cu- is [Ar] 3d10.
d) Br- (Bromine): Bromine belongs to Period 4. The noble gas preceding bromine is krypton (Kr) with an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6. The electron configuration of bromine (Br) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5. Since we have Br-, it means that one electron has been added, resulting in: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6. Thus, the noble gas notation for Br- is [Kr] 4d10 4p6.
e) Sn- (Tin): Tin belongs to Period 5. The noble gas preceding tin is xenon (Xe) with an electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6. The electron configuration of tin (Sn) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p2. Since we have Sn-, it means that one electron has been added, resulting in: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p7. Thus, the noble gas notation for Sn- is [Xe] 4f14 5d10 5p7.