help with some chemistry problems?

Question

1.Neils Bohr’s contribution to modern atomic theory was the proposition that
A.each atom has a specific number of positive charges
B.an atom has electrons i n discrete energy levels
C.electrons have a definite mass that can be computed
D.atomic mass is determined by the number of protons and neutrons in an atom

2.How many grams of nitrogen are present in 2 moles of HNO3?
a.1
b.2
c.14
d.28

3.According to the periodic table, which of the following series of elements is ordered according to decreasing reactivity?
a.He, Cs, Si, Mg
b.Cs, Mg, Si, He
c.Si, H e, Cs, Mg
d.Mg, Si, Cs, He

4.How many moles of copper are equivalent to 3.44 ×1023 atoms of copper?
0.571 moles
a.1.75 moles
b.5.41 × 1021 moles
c.5.71 × 1022 moles

5.What is the molar mass of Al(NO3)3?
a.57 g/mol
b.103 g/mol
c.165 g/mol
d.213 g/mol

Answer 1

B
A
B
0.571 moles
D

Answer 2

1) B
2) D
3) B
4) .571 moles
5) 212.89 D, 213g/mol