By convention the electron configuration / structure of an atom of an element can be shown in form of a diagram using either cross(x) or dot(●) to Practice examples drawing electronic configurations a)11H has - in nucleus1proton and 0 neutrons - 1 electron in the 1st energy levels thus: Nucleus Energy levels Electrons(represented by cross(x) Electronic structure of Hydrogen is thus: 1: b) 42He has - in nucleus 2 proton and 2 neutrons - 2 electron in the 1st energy levels thus: Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Helium is thus: 2: c) 73Li has - in nucleus 3 proton and 4 neutrons - 2 electron in the 1st energy levels -1 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Lithium is thus: 2:1 Kommentar [s1]:
7 d) 94Be has - in nucleus 4 proton and 5 neutrons - 2 electron in the 1st energy levels -2 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Beryllium is thus: 2:2 e) 115B has - in nucleus 5 proton and 6 neutrons - 2 electron in the 1st energy levels -3 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Boron is thus: 2:3 f) 126C has - in nucleus 6 proton and 6 neutrons - 2 electron in the 1st energy levels -4 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Carbon is thus: 2:4 g) 147N has - in nucleus 7 proton and 7 neutrons - 2 electron in the 1st energy levels -5 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x)
8 Electronic structure of Nitrogen is thus: 2:5 h) 168O has - in nucleus 8 proton and 8 neutrons - 2 electron in the 1st energy levels -6 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Oxygen is thus: 2:6 i) 199F has - in nucleus 9 proton and 10 neutrons - 2 electron in the 1st energy levels -7 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Fluorine is thus: 2:7 i) 2010Ne has - in nucleus 10 proton and 10 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels thus Nucleus Energy levels Electrons (represented by cross(x) Electronic structure of Neon is thus: 2:8 j) 2311Na has - in nucleus 11 proton and 12 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels
9 -1 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Sodium is thus: 2:8:1 k) 2412Mg has - in nucleus 12 proton and 12 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -2 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Magnesium is thus: 2:8:2 l) 2713Al has - in nucleus 13 proton and 14 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -3 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Aluminium is thus: 2:8:3 m) 2814Si has - in nucleus 14 proton and 14 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -4 electron in the 3rd energy levels thus Nucleus Energy levels
10 Electrons (represented by dot(.) Electronic structure of Silicon is thus: 2:8:4 n) 3115P has - in nucleus 14 proton and 15 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -5 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Phosphorus is thus: 2:8:5 o) 3216S has - in nucleus 16 proton and 16 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -6 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Sulphur is thus: 2:8:6 p) 3517Cl has - in nucleus 18 proton and 17 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -7 electron in the 3rd energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Chlorine is thus: 2:8:7 p) 4018Ar has - in nucleus 22 proton and 18 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -8 electron in the 3rd energy levels thus Nucleus
11 Energy levels Electrons (represented by dot(.) Electronic structure of Argon is thus: 2:8:8 q) 3919K has - in nucleus 20 proton and 19 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -8 electron in the 3rd energy levels -1 electron in the 4th energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Potassium is thus: 2:8:8:1 r) 4020Ca has - in nucleus 20 proton and 20 neutrons - 2 electron in the 1st energy levels -8 electron in the 2nd energy levels -8 electron in the 3rd energy levels -2 electron in the 4th energy levels thus Nucleus Energy levels Electrons (represented by dot(.) Electronic structure of Calcium is thus: 2:8:8:2
12 B.PERIODIC TABLE There are over 100 elements so far discovered. Scientists have tried to group them together in a periodic table. A periodic table is a horizontal and vertical arrangement of elements according to their atomic numbers. This table was successfully arranged in 1913 by the British scientist Henry Moseley from the previous work of the Russian Scientist Dmitri Mendeleev.