Chapter 2 – Atoms, Molecules, and Ions
____________Albert Kweyete
1. Determine the number of protons, electrons, and neutrons in the followings:
a)
65
Zn
b) cobalt-60
c) sodium
d)
52
Cr3+
e)
130
I-
2. For each of the following elements, write its chemical symbol or name, and indicate the
type and group to which it belongs:
a) potassium
b) arsenic
c) iodine
d) iron
e) Ca
3. Determine the empirical formulas for the following compounds:
a) C6H10O2
b) Si3O9
c) N2O4
e) CH4
4. Predict the charges of the ions of the followings:
a) Al
b) OH
c) O
d) SO4
e) HSO3
f) S4N4
f) ClO
5. Predict the empirical formula for the ionic compounds formed by followings:
a) Ca2+ , PO43b) K+ , NO3−
c) Al3+ , OH−
d) Ba2+ , HCO3−
6. Predict whether each of the following compound is molecular or ionic:
a) NaClO
b) NOCl
c) CoCO3
d) SCl2
7. Give names or chemical formulas for the following acids:
a) H2S
b) Nitric acid
c) perbromic acid
e) H2SO3
f) HClO2
g) Acetic acid
d) HI
h) HCN
8. Provide names or chemical formulas for the followings:
a) Cr(NO3)3
b) silver nitrate
c) Cr2O3
e) Lead(IV) acetate
f) dinitrogen trioxide
g) S4N4
d) Fe(NO2)2
h) KClO
9. Give a chemical formula or name for the followings:
a) chlorate ion
b) oxide ion
c) barium ion
d) hydrogencarbonate ion
e) HSO3f) S2g) Fe3+
h) H3O+
10. Naturally occurring magnesium has the following isotopic abundances:
Isotope Abundance
Mass
Mg-24
78.70%
23.98504
Mg-25
10.13%
24.98584
Mg-26
11.17%
25.98259
Calculate the average atomic mass of magnesium.
e) AlN