[legend45]

ياجماعة عندي كم سؤال منرفزني ممكن مساعدتكم
شبنر 3
Which of the following samples contains the greatest number of atoms?
a) 100 g of Pb
b) 2.0 mole of Ar
c) mole of Fe
d) 5 g of He


A 25.5-g sample of ammonium carbonate contains _______ mol of ammonium ions.
a) 0.468
b) 0.288
c) 0.531
d) 2.00


The atomic masses of 6Li and 7Li are 6.0151 amu and 7.0160 amu, respectively. Calculate the natural abundance
of these two isotopes. The average atomic mass of Lithium (Li=6.941 amu).
a)
6
Li= 7.49% ,
7
Li= 92.51%
b)
7
Li= 7.49% ,
6
Li= 92.51%
c)
6
Li= 8.49% ,
7
Li= 95.51%
d)
7
Li= 7.22% ,
6
Li= 82.51%