Download 1 - VCE Chemistry

Atomic Structure and Metals
Test Preparation
1. Use a diagram (with appropriate explanations) to describe the structure of the atom?
2. What is an isotope?
3. What is the difference between an element and a compound?
4. What is the maximum number of electrons that can be found in the third shell?
5. Make a sketch representing the protons, electrons and neutrons of the calcium atom 20Ca40.
6. Give the electronic structure of the following elements:
a) Phosphorus (15 electrons)
b) Iron (26 electrons)
c) Bromine (35 electrons)
7. What information do the mass number and the atomic number give?
8. Define the term “valence electron”.
9. List as many properties of metals as possible?
10. Describe the structure of a typical metal.
11. What is “metallic bonding”?
12. How can the properties of metals be explained by use of the “metallic bonding model”?
Explain the six properties.
13. What are some of the limitations of the metallic bonding model?
14. What is an alloy?
15. Describe the two ways of forming alloys.
16. Name two alloys and describe their make-up and why the original metal has been changed?
What new properties does it now have?
17. What is metal fatigue, how does it occur and what consequences can result from it?
18. List and describe the three methods of heat treatment?
19. How does an atom become an ion?
20. How many protons, neutrons and electrons does (16O8)-2 have?
The test will consist of multiple-choice questions
and short answer questions.
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Atomic Structure and Metals Test Preparation -Suggested Solutions
1. Something similar to Figure 2.3 on page 10 together with an explanation that captures the key
elements of the ideas on page 10.
2. What is an isotope? See page 11-dot point 5.
3. All atoms in an element have the same atomic number. A compound contains atoms of different
elements chemically combined in fixed proportions.
4. 2n2 = 2 x 32 = 18
5. Make a sketch representing the protons, electrons and neutrons of the calcium atom 20Ca40.
6. Give the electronic structure of the following elements:
a) Phosphorus (15 electrons) 1s2 2s2 2p6 3s2 3p3
b) Iron (26 electrons)
1s2 2s2 2p6 3s2 3p6 4s2 3d6
c) Bromine (35 electrons)
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5
7. Mass number = number of protons while atomic number = number of protons and neutrons
8. “Valence electron” = an electron in the outer shell of an atom
9. List as many properties of metals as possible? See page 24
10. Briefly, a regular three dimensional lattice of positively charged ions (each occupying a fixed place
within the lattice) in a “sea” of negatively charged delocalised electrons – the whole lattice being
held together by the electrostatic attraction of the positive ions and the negative electrons. Diagram
similar to Figure 3.5 is useful.
11. What is “metallic bonding”? The electrostatic attraction of the positive ions and the negative
electrons that holds the metallic lattice in place.
12. See page 27
13. What are some of the limitations of the metallic bonding model? See page 28
14. What is an alloy? A mixture of a metal and another substance (usually a metal). See pages 29 - 30
15. (a) Atoms of similar size are substituted in (b) atoms of smaller size are put in the spaces
16. Choose from steel, stainless steel, bronze, gold, silver, nickel silver, duralumin – pg 30/31
17. Metal fatigue: See page 32 – 34
18. Annealing, Tempering and Quenching – pg 31
19. How does an atom become an ion? By gaining or losing electrons
20. 8 protons, 8 neutrons and 10 electrons
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Salesian College – Chadstone
V.C.E. Chemistry - Unit 1
Atomic Structure and Metals Test
PART A - MULTIPLE CHOICE [1 mark each]
1. The fundamental particles found in the nucleus of the atom are:
A) Protons only
B) Neutrons only
C) Protons and neutrons
D) Electrons and neutrons
E) Electrons only
2. The structure of a metal crystal can be described as
A) Atoms covalently bonded to one another
B) Positive ions with the excess electrons forming an electron cloud dispersed through the lattice
C) Atoms with positively and negatively charged ions dispersed through the lattice.
D) Positively and negatively charged ions alternating through the lattice.
E) A series of crystals held together by hydrogen bonding.
3. An atom becomes an ion when
A) Its gains or loses protons
B) It gains or loses electrons
C) Its atomic number changes
D) Its mass number changes
E) Both its atomic number and its mass number change
4. A group in the periodic table is identified as:
A) Elements with the same electronegativity
B) A column of the periodic table
C) A row of the periodic table
D) Elements with different numbers of valence electrons
E) Elements with identical electronic configurations
5. Bromine and iodine are in the same group in the Periodic Table. A bromine atom and an iodine
atom would be expected to have
A) The same electronic configuration
B) The same number of protons in their nuclei
C) Similar chemical properties
D) Similar atomic mass
E) No similarities at all.
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6. Sucrose (C12H22O11) is an example of
A) an atom
B) an element
C) a compound
D) a mixture
E) none of the above
7. An ion, X2+ has the electronic structure 1s2 2s2 2p6 3s2 3p6. The element X
A) has no valence electrons
B) is a noble gas
C) is metallic
D) may be found in the third period of the Periodic Table
E) may be found in group three of the Periodic Table
207
X4+
8. If an atom is represented by
it would possess
82
A) 82 protons, 82 electrons and 121 neutrons
B) 82 protons, 86 electrons and 125 neutrons
C) 86 protons, 82 electrons and 125 neutrons
D) 82 protons, 78 electrons and 125 neutrons
E) 78 protons, 82 electrons and 121 neutrons
9. The group containing only compounds is
A) CH4, H3PO4, S8
B) NO2, P4, H2O
C) H2SO4, SF6, PH3
D) NaCl, N2, P4O10
E) He, Mg, Ne
10. Metals are
A) Lustrous, soft and malleable
B) Soft, good conductors of heat and ductile
C) Malleable, good conductors of heat but not of electricity
D) Ductile, good conductors of electricity and of heat
E) Malleable, good conductors of electricity but are not lustrous.
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Part A
Part B
TOTAL
%
/10
/40
/50
%
Name:____________________
Salesian College – Chadstone
V.C.E. Chemistry - Unit 1
Atomic Structure and Metals Test
PART A - MULTIPLE CHOICE [1 mark each]
Circle the correct answer in each case:
1. A
B
C
D
E
2. A
B
C
D
E
3. A
B
C
D
E
4. A
B
C
D
E
5. A
B
C
D
E
6. A
B
C
D
E
7. A
B
C
D
E
8. A
B
C
D
E
9. A
B
C
D
E
10.A
B
C
D
E
PART B - SHORT ANSWER
1. Write down the electronic configuration of Selenium, which has 34 electrons.
[2 marks]
2. Give a brief explanation of the following facts: “The radius of an atom is approximately 10,000
times the radius of the nucleus, yet the atom’s mass is very close to the mass of its nucleus.
[2 marks]
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3. Complete the following table:
Atom
or ion
Number of
protons
Number of
neutrons
Electronic
configuration
25
12Mg
16
28O
[3 marks]
4. The name isotopes in Greek means “same place”.
a) What is an isotope?
b) Explain why isotopes of a particular element are all found in the same place in the Periodic
Table.
[3 marks]
5. With the aid of a clearly labeled diagram, explain the structure and bonding of a metal.
[5 marks]
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6. Use the ionic bonding model to explain the following properties of ionic compounds:
they generally have high melting temperatures
they are hard and brittle
they do not conduct electricity in the solid state
but will conduct electricity when molten or
dissolved in water
[3 marks]
7. Use a diagram to show the transfer of electrons that occurs when magnesium reacts with
fluorine.
[2 marks]
8. Use the valency table (back of periodic table) to writ the empirical formula for each of the
following:
a) sodium hydroxide
b) copper (II) sulfate
c) ammonium nitrate
d) aluminium sulfite
e) sodium hydrogen phosphate
[5 marks]
9. A student compares the structure and bonding in metals with that in ionic compounds and
makes the following statements. Comment on each of thmn, explaining clearly whether you
agree or disagree.
a. a metal will conduct electricity whereas an ionic solid will not because the electrons
are much smaller than negative ions.
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b. metals and ionic solids both contain positive ions in a regular arrangement.
[4 marks]
10. In the Modifying Metals practical, we changed the properties of metals depending on the rate of
cooling. How does the rate of cooling affect the properties of metals?
[2 marks]
11. There are two types of alloys. For each type, draw a diagram illustrating the atoms, explain
what is happening
Type
of
alloy
Diagram
Explanation
#1
#2
[4 marks]
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12. The electronic configurations of six elements (A-F) are listed below. The symbols used do not
correspond o the actual symbols of the elements.
Element A
1s2 2s2 2p2
Element B
1s2 2s2 2p4
Element C
1s2 2s2 2p5
Element D
1s2 2s2 2p6
Element E
1s2 2s2 2p6 3s2 3p1
Element f
1s2 2s2 2p6 3s2 3p5
Use the element letters A-F to answer the following:
a) Which element is a metal? ______
b) Which elements are in the same group in the Periodic Table? ______ & ______
c) Name one element that is in Period 3 of the Periodic Table. ______
d) Which element is the least reactive? ______
e) Which element forms cations? ______
[5 marks]
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