1.a. Cd , Z = 48 => 48p⁺ si 48e⁻ ; A = 112 , A = Z+N => N = A-Z = 112-48 = 64n⁰
b. P, Z = 15 ; 1s² / 2s² 2p⁶ / 3s² 3p³
2 . Atomul reprezinta cea mai mica particula a unui element , indivizibil.
3. n = V/Vm = 56/22,4 = 2,5 moli N₂
nr atomi N₂ = 2*2,5*NA = 5*6,022*10^23 = 3,011*10²⁴
4. pV = m/MRT => M = mRT/pV = 320*0,082*500/41*10 = 32g/mol
5. a. Z = 16 => sarcina nucleara + 16
b. ⇅↑↑ ; 2 orbitali monoelectronici de tip p
