150 likes | 244 Views
Group members . Sherab Chophel ( BE 102100) Shreejana Bomjan (BE102101) Sonam Tshering (BE 1020102. Period. The horizontal row shown in the periodic table are called period or simply rows. There are seven period in the periodic table.
E N D
Group members Sherab Chophel ( BE 102100) Shreejana Bomjan (BE102101) Sonam Tshering (BE 1020102
Period The horizontal row shown in the periodic table are called period or simply rows. There are seven period in the periodic table. • 1st period consists of 2 elements which are hydrogen(Z=1) and Helium(z=2) • 2nd and 3rd period have 8 elements each. • 4th and 5th period have 18 elements while 6th period have 32 elements. • 7th period is incomplete periods and at present it consists of 19 elements.
Elements in period II 1. Lithium (Li) • Atomic number = 3 • Electronic configuration=1s22s1 • Element category= metal
2. Beryllium(Be) • Atomic number= 4 • Electronic configuration=1s22s2 • Element category= metal
3. Boron (B) • Atomic number= 5 • Electronic configuration= 1s2 2s2 2p1 • element category= non-metal
4. Carbon (C) • Atomic number= 6 • Electronic configuration= 1s2 2s2 2p2 • Elementary category= non- metal
5. Nitrogen(N) • Atomic number= 7 • Electronic configuration= 1s2 2s2 2p3 • Elementary category= non- metal
6. Oxygen(O) • Atomic number=8 • Electronic configuration= 1s2 2s2 2p4 • Element category= non-metal
7. Fluorine(F) • Atomic number=9 • Electronic configuration= 1s2 2s2 2p5 • Element category= non-metal
electro negativity • The tendency to pull the electrons towards itself is called electro negativity. The fluorine is the highly reactive elements in a period Since fluorine has 7 electrons in the outermost shell. So in order to be in stable state it need 1 election. So it pulls the electron towards it and gains negative charge.
8. Neon (Ne) • Atomic number=10 • Electronic configuration= 1s2 2s2 2p6 • Element category= non-metal
general characteristics of periods • Number of valence electrons: • The number of valences increases from 1 t0 8 when we proceed from left to right on a period. • valency: The valency of elements increases from 1 to 4 and falls to 1. • Size of atoms- The size of the atoms decreases from left to right in a period. Thus a alkali metals have the largest size while the halogen have the smallest size. This is because energy required to remove an electron from atom increases when we move from left to right in period.
- • Metallic character- On moving form left to right in a period the metallic character of the elements decreases. • Number of shells: In going from left to right in a period number of electron shell remain same.