Stii ca 1 mol H2O = 18 g
Stii ca 1 Km = 1000 moli
Deci 2 Km H2O = 2 x 1000 x 18 = 36000 g (36 kg).
Faci regula de 3 simpla.
1 mol...... 6,023 x 10^23
2000 moli........ x
x= 2000 x 6,023 x 10^23 = 12,046 x 10^26 molecule H2O
Daca e sa luam nr. de atomi, stim ca:
1 molecula H2O = 2 atomi H + 1 atom H = 3 atomi
Si atunci inmultim cu 3:
12,046 x 10^26 x 3 atomi
