St Mary’s Catholic
School
Chemistry-Groupwork
Group Members’ Name
No
1. Befiker Tilahun
3
2. Belen Dereje
4
3. Hasset Emishaw
16
4. Soliana Abebe
5. Tsion Dawit
48
6. Yedideya Melaku
Submitted to: Mr.
Sintayehu Habtie
Submission Date: 16/03/2017 E.C
Choose the correct answer from the given alternatives.
1. Which of the following scientists did not contribute to determining the
structure of the atom? a. Thomson b. Rutherford c. Becquerel d.
Dalton 1
2. What is the frequency in Hz of the gamma radiation from a radioactive
cobalt-60 source if its wavelength is 1.0 x 10^-9 nm? a. 3.3 x 10^-27
Hz b. 3.3 x 10^-8 Hz c. 3.0 x 10^18 Hz d. 3.0 x 10^-26 Hz
3. What is the energy of the electronic transition associated with the
sodium-D line having a wavelength of 589 nm? a. 6.63 x 10^-34 J b.
1.13 x 10^-27 J c. 3.38 x 10^-19 J d. 5.82 x 10^2 J
4. Among the following, which color corresponds to light of the highest
frequency? a. Green b. Red c. Yellow d. Blue
5. Which of the following orbital designations does not exist? a. 1s b. 2d
c. 3p d. 4f
6. Which of the following sets of quantum numbers are not allowed in the
hydrogen atom? a. n = 3, l = 2, m_t = 2 b. n = 4, l = 3, m_t = 4 c. n =
1, l = 0, m_t = 0 d. n = 2, l = 1, m_t = -1
7. The species that has the same number of electrons as ^32S is: a.
^31Cl b. ^33P+ c. ^34S+ d. ^28Si^2-
8. Which of the following has the lowest electronegativity? a. Carbon b.
Magnesium c. Beryllium d. Boron
9. How many unpaired electrons are there in the Cr^3+ ion? a. 0 b. 1 c. 2
d. 3
10. Which of the following species would require the highest energy
for the removal of one electron? a. Mg^2+ b. Na+ c. Ne d. F
Complete the following statements.
11. The atomic number gives the number of ______ in the nucleus.
12. In an atom, the number of electrons is equal to the number of
______.
13. When n=2, the values of l could be ______ and ______.
14. When l=1, the values of m_t could be ______, ______, and ______,
as well as the subshell has the letter label ______.
15. When l=1, the subshell is called a ______ subshell with ______
total orbitals.
16. When the subshell is labeled p, there are ______ values of m_t
and ______ orbitals occur within the subshell.
17. When the subshell is labeled f, there are ______ values of m_t and
______ orbitals occur within the subshell.
Short answer questions and problems.
18. For the following atoms, determine the number of protons,
neutrons, and electrons:
a. 48114 Cd b. 4399 Tc c. 79190 Au d. 86227 Rn
1
19. Iridium has two naturally occurring isotopes. 191Ir and 193Ir
have atomic masses of 190.9609 amu and 192.9633 amu,
respectively. The average atomic mass for iridium is 192.22 amu. What
is the percent natural abundance for each isotope?
2
20. The following are representative wavelengths in the IR, UV and
X-ray regions of the electromagnetic spectrum, 1.0</0>×10−6m,
1.0×10−8m and 1.0×10−10<2>m, respectively.
a. What is the energy of a photon form each transition? b. Which of them has
the highest energy per photon?
21. What is the wavelength of a beam of protons having a velocity of
1.38</2>×107cm/s? The mass of a proton is 1.76×10−24kg.
22. The photon emitted by a cyclotron has a velocity of
1.50×103m/s. What is the wavelength of this photon? The mass of
photon =1.676×10−27kg and Planck's constant =6.62×10−34J.s.
23. Calculate the wavelength of the light emitted when an electron
falls from n = 3 to the n = 1 state in a hydrogen atom.
24. Write the number and the letter for the orbital that corresponds
to the following pairs of n and l quantum numbers:
a. n = 3, l = 1 b. n = 4, l = 0 c. n = 3, l = 2 d. n = 5, l = 3
1 2
25. What type of orbital (i.e. 3s, 4p, ...) is designated by these
quantum numbers?
a. n = 5, l = 1, m = 0 b. n = 4, l = 2, m = -2 c. n = 2, l = 0, m = 0 d. n = 4, l
= 3, m = -3
26. Write the ground-state electron configurations for the following
elements:
a. Br (Z = 35) b. Mo (Z = 42) c. W (Z = 74)
27. Write the period number for each of the following and state if
they are metal, non-metal or metalloid:
3
a. P b. Ge c. F d. W
