PDF Archive

Easily share your PDF documents with your contacts, on the Web and Social Networks.

Share a file Manage my documents Convert Recover PDF Search Help Contact



G1 Review Questions Update .pdf


Original filename: G1 Review Questions Update.pdf
Title: G1 Review Questions
Author: Chad

This PDF 1.4 document has been generated by Acrobat PDFMaker 6.0 for Word / Acrobat Distiller 6.0 (Windows), and has been sent on pdf-archive.com on 23/01/2017 at 23:26, from IP address 69.125.x.x. The current document download page has been viewed 384 times.
File size: 124 KB (14 pages).
Privacy: public file




Download original PDF file









Document preview


Gen Chem Day 1 Review Questions
1) How many protons, electrons and neutrons does
A) 84 protons, 82 electrons, 126 neutrons
B) 82 protons, 80 electrons, 126 neutrons
C) 82 protons, 82 electrons, 128 neutrons
D) 82 protons, 80 electrons, 128 neutrons

208
82

Pb 2+ have?

2) What is the electronic configuration of Cu+?
A) 1s22s22p63s23p64s23d8
B) 1s22s22p63s23p64s13d9
C) 1s22s22p63s23p64s13d8
D)
1s22s22p63s23p63d10
3) Which of the following is the electron configuration of an element in an excited state?
A) 1s22s22p63s23p64s23d8
B) 1s22s22p63s23p64s13d10
C) 1s22s22p63s23p64s24d1
D) 1s22s22p63s23p5
4) Which of the following is the electron configuration of Se?
A) 1s22s22p63s23p64s13d104p5
B) 1s22s22p63s23p64s23d104p65s24d105d4
C) [Ar]5s24d105p4
D) 1s22s22p63s23p64s23d104p4
5) Which of the following is the electron configuration of Cl-?
A) 1s22s22p63s23p5
B) 1s22s22p63s23p6
C) 1s22s22p63s23p64s23d104p6
D) 1s22s22p63s23p4
6) Which of the following is a possible set of quantum numbers [n,l,ml,ms] for a valence
electron in bromine?
A) [4,0,0,-1/2]
B) [3,1,1,+1/2]
C) [4,1,-2,+1/2]
D) [3,2,-1,-1/2]
7) Which of the following is a possible set of quantum numbers [n,l,ml,ms] for an
electron?
A) [3,3,0,-1/2]
B) [3,2,1,-1]
C) [5,0,0,-1/2]
D) [4,1,2,+1/2]

8) How many orbitals does the fourth shell (n = 4) of an atom contain?
A) 9
B) 16
C) 18
D) 32
9) How many electrons maximum can occupy the third shell (n = 3) of an atom?
A) 9
B) 16
C) 18
D) 32
10) Which of the following is paramagnetic?
A) ClB) Ag
C) Mg2+
D) Cu+
11) Which of the following is diamagnetic?
A) Ca+
B) Mn2+
C) Fe3+
D) Cu+
12) Which of the following is most likely to decay by alpha emission?
A) sodium -23
B) uranium-235
C) carbon-14
D) helium-4
13) Which of the following is most likely to decay by beta emission?
A) calcium-40
B) oxygen-16
C) carbon-14
D) nitrogen-14
14) Which of the following result in the conversion of a proton into a neutron?
A) Positron emission
B) Beta decay
C) Electron capture
D) Both A and C

15) Which of the following is most likely to be radioactive?
A) oxygen-16
B) carbon-12
C) gold-196
D) magnesium-24
16) What is the product of alpha decay of 210Po?
A) lead-206
B) mercury-208
C) radon-214
D) polonium-208
17) What is the product of electron capture of 20Na?
A) magnesium-20
B) neon-20
C) sodium-21
D) sodium-19
18) What is the product of gamma emission of 60Co?
A) nickel-60
B) iron-60
C) manganese-56
D) cobalt-60
19) What is the missing nuclide in the following nuclear
1
4
0
reaction? 235
92 U + 0 n →3 2 α + 2 −1 β + ?

A)

232
91

Pa

B)

224
88

Ra

C)

224
87

Fr

D)

232
92

U

20) The half-life of a radioactive nuclide is 2.5hrs? What fraction of a sample of this
nuclide would remain after 12.5 hrs?
A) 1/8
B) 1/16
C) 1/32
D) 1/64
21) After 18hrs 87.5% of a sample of a radioactive nuclide has decayed. What is its halflife?
A) 36 hrs
B) 54hrs
C) 9hrs
D) 6hrs

22) How much of a 32g sample of a radioactive nuclide would remain after 6 half-lives?
A) 0.25g
B) 0.5g
C) 1.0g
D) 2.0g
23) The half-life of a radioactive nuclide is 2.05 hrs. What percentage of a sample of this
nuclide would remain after 8hrs?
A) 6.7%
B) 13%
C) 5.5%
D) 27%

Gen Chem Day 1 Answer Key

1) How many protons, electrons and neutrons does
A) 84 protons, 82 electrons, 126 neutrons
B) 82 protons, 80 electrons, 126 neutrons
C) 82 protons, 82 electrons, 128 neutrons
D) 82 protons, 80 electrons, 128 neutrons

208
82

Pb 2+ have?

The atomic #, 82 is always the number of protons.
The mass #, 208 is the sum of the protons and neutrons.
Therefore p + n= 208 so n = 208 – p = 208 – 82 = 126
Finally, p – e = charge so 82 – e = +2 and so e = 80
2) What is the electronic configuration of Cu+?
A) 1s22s22p63s23p64s23d8
B) 1s22s22p63s23p64s13d9
C) 1s22s22p63s23p64s13d8
D) 1s22s22p63s23p63d10
You have to start from the ground state configuration of Cu: 1s22s22p63s23p64s13d10.
Cu, Ag, and Au are all exceptions and end with s1d10, not s2d9. To make Cu+ we need to
remove 1 electron and we have to remember to remove electrons from the highest shell #
first (4s before 3d in this case) leaving us with 1s22s22p63s23p63d10. This is often
something we only need worry about with transition metals.
3) Which of the following is the electron configuration of an element in an excited state?
A) 1s22s22p63s23p64s23d8
B) 1s22s22p63s23p64s13d10
C) 1s22s22p63s23p64s24d1
D) 1s22s22p63s23p5
Evidence of an element being in the excited state is that there is an electron(s) in a higher
energy orbital before the lower energy ones are filled. But don’t forget the 5 exceptions
you’re expected to remember: Cr and Mo end with s1d5, and Cu, Ag, and Au all end with
s1d10 in the ground state. Therefore choice B is an exception and is the ground state of
Cu and can be ruled out. Choice C describes an excited state as there is an electron in the
4d subshell before the 3d, 4p, and 5s subshells are full.

4) Which of the following is the electron configuration of Se?
A) 1s22s22p63s23p64s13d104p5
B) 1s22s22p63s23p64s23d104p65s24d105d4
C) [Ar]5s24d105p4
D) 1s22s22p63s23p64s23d104p4
Selenium’s ground state configuration is 1s22s22p63s23p64s23d104p4 or [Ar]4s23d104p4.
Choice A has 1 too many electrons and is the electron configuration of Br.
Choice B is the electron configuration of Te.
Choice C doesn’t correspond to any element as the shell numbers are all off by 1.
5) Which of the following is the electron configuration of Cl-?
A) 1s22s22p63s23p5
B) 1s22s22p63s23p6
C) 1s22s22p63s23p64s23d104p6
D) 1s22s22p63s23p4
Cl- has 1 more electron than Cl and therefore is isoelectronic with Ar. Therefore [Ar],
[Ne]3s23p6, and 1s22s22p63s23p6 are all acceptable electron configurations for Cl-.
Choice A is the electron configuration of atomic Cl.
Choice C is the electron configuration of Br-.
Choice D is the electron configuration of Cl+.
6) Which of the following is a possible set of quantum numbers [n,l,ml,ms] for a valence
electron in bromine?
A) [4,0,0,-1/2]
B) [3,1,1,+1/2]
C) [4,1,-2,+1/2]
D) [3,2,-1,-1/2]
The electron configuration of Br is 1s22s22p63s23p64s23d104p5. The 4s and 4p electrons
are considered the 7 valence electrons of Br and so the set of quantum numbers could
describe an electron in either the 4s or 4p subshells. To be in the 4th shell, n=4 which
eliminates choices B and D. To be in an s or p subshell, l=0 (s) or l=1 (p) so so far
choices A or C could work. But ml is restricted in being an integer between –l and +l.
This rules out choice C as -2 is not between -1 and 1. That leaves choice A. Incidentally,
ms can only have values of +1/2 or -1/2.

7) Which of the following is a possible set of quantum numbers [n,l,ml,ms] for an
electron?
A) [3,3,0,-1/2]
B) [3,2,1,-1]
C) [5,0,0,-1/2]
D) [4,1,2,+1/2]
In a question like this one, the first place to look is at ms which must equal +1/2 or -1/2.
This eliminates choice B. Next look at the relationship between l and n; l has to be
smaller than n. This eliminates choice A. Lastly, look at the relationship between ml and
l; ml has to be an integer between –l and +l. This eliminates choice D.
8) How many orbitals does the fourth shell (n = 4) of an atom contain?
A) 9
B) 16
C) 18
D) 32
The shortcut is that there are n2 orbitals in each shell. So the 4th shell has 42 or 16 orbitals.
9) How many electrons maximum can occupy the third shell (n = 3) of an atom?
A) 9
B) 16
C) 18
D) 32
There are n2 orbitals in each shell and each orbital can hold a maximum of 2 electrons
and so the maximum number of electrons held by any shell is 2n2. For the 3rd shell there
are 32 or 9 orbitals which can hold a maximum of 18 electrons.

10) Which of the following is paramagnetic?
A) ClB) Ag
C) Mg2+
D) Cu+
An atom is paramagnetic if it has unpaired electrons. The quick route here is to first see
how many electrons each species has; if it has an odd number of electrons, then it must
have unpaired electrons.
Cl- has 18 electrons
Ag has 47 electrons
Mg2+ has 10 electrons
Cu+ has 28 electrons.
Ag is the only species with an odd number of electrons and must be the correct answer.
Note that even though an odd number of electrons indicates the presence of unpaired
electron(s), the converse isn’t necessarily true. Just because a species has an even
number of electrons doesn’t mean it doesn’t have any unpaired electrons. If every
answer choice had an even number of electrons, further inspection of the electron
configuration would have been required. In the ground state, all of the core electrons will
be paired so we need only examine the valence electrons so it is convenient only to look
at the noble gas configuration.
Cl-: [Ar]
Ag: [Kr]5s14d10
Mg2+: [Ne]
Cu+: [Ar]3d10
Upon further inspection we can see silver’s unpaired electron in the 5s orbital. We can
also see that the other 3 species all have filled shells or subshells and therefore don’t have
any unpaired electrons.

11) Which of the following is diamagnetic?
A) Ca+
B) Mn2+
C) Fe3+
D) Cu+
An atom is diamagnetic if it contains no unpaired electrons. . The quick route here is to
first see how many electrons each species has; if it has an odd number of electrons, then it
must have unpaired electrons and can be eliminated.
Ca+ has 19 electrons
Mn2+ has 23 electrons
Fe3+ has 23 electrons
Cu+ has 28 electrons
Cu+ is the only species with can be diamagnetic as the other 3 will have unpaired
electrons having an odd number of electrons. Further inspection of the electron
configuration of Cu+ confirms that it is indeed diamagnetic as all its shells and subshells
are full.
Cu+: [Ar]3d10
12) Which of the following is most likely to decay by alpha emission?
A) sodium -23
B) uranium-235
C) carbon-14
D) helium-4
Alpha emission is most likely for the very heavy elements (Z > 83). Out the the answers
listed, only uranium-235 has an atomic number greater than 83.


Related documents


g1 review questions update
chemistry full notes
gen chem review guides days 1 7 hd 2
jan 13 ms
principle of electronics by v k mehta
jun 14 ms


Related keywords