Tin
Chemical Element
Tin is a chemical element with the symbol Sn and atomic number 50. It is a main group metal in group 14 of the periodic table. Wikipedia
Symbol: Sn
Electron configuration: [Kr] 4d105s25p2
Atomic number: 50
Melting point: 449.5°F (231.9°C)
Atomic mass: 118.71 u
Boiling point: 4,717°F (2,603°C)
Electrons per shell: 2, 8, 18, 18, 4
Answer:
(a) (i) All the elements of a group have similar chemical properties because they have same no. of valence electrons in their outermost shell. (ii) All the elements of a period have different chemical properties because they have different no. of valence electrons in their atoms.
1- One mole is = 6.02 x 10^23 of anything, So one mole of atoms is 6.02x10^23.
2- when the balloon contains 0.15 moles of Co2 gas so:
the no.of molecules of Co2 = 0.15 x 6.02x 10^23
= 9.0 x 10^22
