CHEM 1411 - CHAPTER 7
ATOMIC STRUCTURE AND PERIODICITY
1. Calculate the following
a) Frequency of a radiation with wavelength is 460 nm.
b) Energy of a photon of frequency 5.20x1011 s-1.
c) Wavelength of radiation with photons of energy 3.70x10-17 J.
2. (a) What is the velocity of a neutron( m = 1.67x10-24 g) which exhibits a wavelength of 580 nm?
(b) Calculate the wavelength of an electron ( me = 9.11x10-28 g) which travels at velocity of 500.0 m/s.
3. Consider the third energy level (third shell), n=3;
a) Predict the number of orbital (sub shells) and label each orbital.
b) Determine the maximum number of electrons.
c) Identify l and ml values for this energy level.
4. Determine the following quantities;
a) Total number of electrons in n=4.
b) Total number of electrons in n=3 , l=2.
c) Total number of electrons in n=1, l=0, m=0.
d) Total number of electrons in n=1,l=0, m=0, s=+1/2.
e) Total number of electrons in 2p orbital.
f)
Total number of orbital in 3d.
g) Orbital designation for n=4, l=3.
h) Orbital designation for n=1, l=1.
i)
Orbital designation for n=3, l=1, m=-2.
j)
Orbital designation for n=2, l=1, m=-1, s=+1/2.
5. Circle the orbital with highest energy (least effective nuclear charge);
(a) 1s,2s,3s
(b) 2s,2p,3p
(c) 3d,2p,2s
(d) 4s,4p, 4f
6. Consider the following atoms and ions; Cr, Cr3+, Bra) Write electron configuration
b) Write core configuration
c) Determine the total number of unpaired electrons in Cr
d) Identify paramagnetic and diamagnetic species
7. Identify the following as excited state (ES) or ground state (GS);
a) 1s2 2s2 2p2
d) 1s2 2s1 2p3
b) 1s2 2s2 2p6 3s1 3p6
e) 1s2 2s2 2p3
c) 1s2 2s2 2p6 3s2 3p64s1 3d10
f) 1s1 2s2
9. Identify the isoelectronic pairs in each set.
a) Na+ and Ne
b) F- and S2-
c) Ca2+ and K+
d) Cl - and Ne