Download Study guide for percent abundance chapter 4 spaced out

Study guide for chapter 4
1. State the number of protons, electrons and neutrons in the
15
N3-.
7
2. The element vanadium has two isotopes, 50V and 51 V, and a relative atomic
mass of 50.94. (5pts)
a. Define the term isotope.
b. State the number of protons, electrons and neutrons in 50V.
c. State and explain which is the more abundant isotope.
d. State the name and the number of the isotope relative to which all atomic
masses are measured.
3. Describe and explain the operation of a mass spectrometer (5)
a. State three factors that affect the degree of deflection of ions in a mass
spectrometer
b. Calculate the relative atomic mass of strontium to two decimal places
from the following data.
c.
Isotope
Percentage abundance
Sr-84
.56
Sr 86
9.90
Sr-87
7.00
Sr-88
82.54
4. State a physical property that is different for isotopes of an element.
5.
a. Chlorine exists as two isotopes, 35 Cl and 37Cl. The relative atomic
mass of chlorine is 35.45. Calculate the percentage abundance of each
isotope.
6. A sample of argon exists as a mixture of three isotopes. Calculate the
relative abundance of argon.
Isotope
Ar-36
Ar-38
Ar-40
percent abundance
.337
0.0630
99.6
7. State the number of electrons, protons and neutrons in the ion 56Fe.
8. Define the following terms
9.
a. Atomic number
b. Mass number
c. Use the data below to calculate the relative molecular mass of thallium
bromide, TiBr3, to two decimal places .
Isotope
203
Tl
205
Tl
79
Br
81
Br
Percentage abundance
29.52
70.48
50.69
49.31
10. In a sample of gallium, the percentage abundance of 69Ga is 60.4, and 71Ga
is 39.6. Determine the relative mass of gallium.
b. Describe the difference between a continuous spectrum and a line
spectrum.
c. On the diagram below draw four lines in the visible line spectrum of
hydrogen. Explain how the formation of lines indicates the presence of
energy levels.
Low energy
high energy
11.Which statement is correct about a line emission spectrum?
a.
b.
c.
d.
Electrons absorb energy as they move from low to high energy levels.
Electrons absorb energy as they move from high to low energy levels.
Electrons release energy as they move from low to high energy levels.
Electrons release energy as they move form high to low energy levels.
12.A sample of the element chromium contains four isotopes, as shown in the
table below.
Calculate the relative atomic mass of chromium in the sample, giving your
answer to two decimal places.
Isotope
50
Cr
52
Cr
53
Cr
54
Cr
Percentage abundance
4.30
83.8
9.50
2.40
13. How many protons, neutrons and electrons are present in each atom of
31
P?
14.How many protons, neutrons and electrons are present in each atom of 19F?
15.Which statement is correct for the emission spectrum of the hydrogen
atom?
a. The lines converge at lower energies
b. The lines are produced when electrons move from lower to higher
energy levels
c. The lines in the visible region involve electron transition into the energy
level closest to the nucleus.
d. The line corresponding to the greatest emission of energy is the
ultraviolet region.
16.A certain sample of element Z contains 60% of 69Z and 40% of 71Z. What is
the relative atomic mass of element Z in the sample
17.What is the difference between two neutral atoms represented by the
symbols 59Co and 59 Ni?
27
28
15. How many electrons are there in on 24 Mg2+ ion?
12
18.Information is given about four different atoms. Which two atoms are
isotopes
Species
W
X
Y
Z
Number of
protons
9
11
12
13
Number of
neutrons
10
12
12
14
Number of
electrons
10
11
12
10
19.Tritium, 3 T, is an isotope of hydrogen.
a. State the number and type of sub-atomic particles in a tritium atom and
the location of each type.
20.Eelctrons are directed into an electric field form left to right as indicated by
the arrow in the diagram below. Which path is most probable for these
electrons?
+
1
2
-
4
3
21.How many neutrons are there in the ion 18 O2-.
22.Which statements are correct for the emission spectrum of the hydrogen
atom?
I.
The lines converge at lower energies
II.
Electron transitions to n=1 are responsible for lines in the UV region.
III.
Lines are produced when electrons move from higher to lower
energy levels.
23.Which process is responsible for the lines in the visible emission spectrum
of hydrogen
b. The release of energy by the electron
c. The release of energy by the excited nucleus
d. The excitation of the electron
e. The absorption of energy by the electron