Unit 3 – The Atom
Practice Test KEY
1)
Which atomic theorist was the first to discover a subatomic particle?
A) Democritus
2)
B) Schrödinger
C) Thomson
D) Dalton
Select the correct statement about subatomic particles.
A) Neutrons have a negative charge and are the heaviest subatomic particle.
B) Electrons are negatively charged and are the heaviest subatomic particle
C) The mass of a neutron is negligible.
D) Electrons are negatively charged and are located in the nucleus.
E) Protons are positively charged and have about the same mass as a neutron.
3)
The model of the atom proposed by Niels Bohr depicted what kind of structure?
A) A model in which the nucleus is made of electrons and protons
B) A model in which the electrons orbit the nucleus in concentric circles.
C) A model in which the nucleus is made of neutrons only
D) A model in which the nucleus is made of protons, neutrons, and electrons
E) A model in which the protons, electrons, and neutrons are evenly distributed throughout the volume of the atom.
4)
Which of the following shows a valid symbol?
A)
5)
B)
C)
D)
How do the isotopes of hydrogen-1 and hydrogen-2 differ?
A) hydrogen-2 is heavier than hydrogen-1
B) hydrogen-1 has a charge of (-1); hydrogen-2 has charge of (-2)
C) hydrogen-2 is more naturally abundant than hydrogen-1
D) hydrogen-1 has an atomic number of 1; hydrogen-2 has an atomic number of 2
6)
What are the appropriate labels for the symbol:
A) X = symbol, A = atomic number, B = mass number, C = charge
B) X = symbol, A = mass number, B = atomic number, C = charge
C) X = symbol, A = atomic mass, B = atomic number, C = charge
D) X = symbol, A = atomic mass, B = mass number, C= charge
E) None of these
7)
The number of _____________ in an atom is unique to each element.
A) protons
B) neutrons
C) electrons
D) isotopes
E)
8)
9)
Who designed the first periodic table of the elements, and how was it organized?
A) Dmitri Mendeleev, by atomic number
B) Henry Moseley, by atomic number
C) Dmitri Mendeleev, by atomic mass
D) Henry Moseley, by atomic mass
Which of the following indicates a valid pair of isotopes?
2
H has 1 neutron, H has 2 neutrons
238
239
B)
U has 146 neutrons,
U has 146 neutrons
39
40
C)
K has 19 neutrons, K has 20 neutrons
24
25
D)
Mg has 12 neutrons, Mg has 13 neutrons
A)
10)
1
Which two of the following symbols indicate the same number of neutrons?
I.
A) I and IV
11)
II.
B) I and II
III.
IV.
C) II and III
D) III and IV
Assuming there are only 2 isotopes in existence for a particular element, which of the following statements would be
correct?
9
10
A) Be is more abundant than Be
13
12
B)
C is more abundant than C
83.8
84.8
C)
Kr is more abundant than
Kr
14
13
D)
Al is more abundant than Al
12)
Consider an element Z that has two naturally occurring isotopes with the following percent abundances: the isotope with
a mass number of 32 is 35% abundant; the isotope with a mass number of 34 is 65% abundant. What is the average
atomic mass for element Z?
A) 32 amu
13)
B) 32.5amu
C) 33amu
Which model of the atom was a direct result of the discovery of the electron?
A) the nuclear model of the atom
B) the planetary model of the atom
C) the plum pudding model of the atom
D) 33.3amu
E) 66amu
14)
The angular quantum number indicates what property of an electron?
A) sublevel
15)
D) momentum
C)
D)
E) spin
B)
What is the maximum number of electrons in the p sublevel?
A) 4
17)
C) orbital orientation
What is the shape of the 3d atomic orbital?
A)
16)
B) energy level
B) 6
C) 5
D) 3
E) 2
Which of the following shows a proper account of the maximum 18 electrons in the third principal energy level?
A) 2 electrons in the 3s sublevel, 10 electrons in the 3p sublevel, 6 electrons in the 3d sublevel
B) 2 electrons in the 3s sublevel, 6 electrons in the 3p sublevel, 2 electrons in the 4s sublevel, 8 valence electrons
C) 2 electrons in the 3s sublevel, 6 electrons in the 3p sublevel, 10 electrons in the 3d sublevel
D) 2 electrons in the 3s sublevel, 14 electrons in the 3f sublevel, 2 electrons in the 4s sublevel
E) 2 electrons in the 3s sublevel, 10 electrons in the 2d sublevel, 6 electrons in the 3p sublevel
18)
What types of atomic orbitals are in the fourth principal energy level?
A) s and p only
19)
B) p and d only
C) s, p, and d only
D) s, p, d and f
E) s only
Which of the following correctly defines Hund’s Rule?
A) electrons will fill in orbitals of lower energy before they fill orbitals of higher energy
B) no two electrons in an atom can have the same set of four quantum numbers
C) two electrons in the same orbital must be spinning in opposite directions
D) both the position of an electron and its velocity cannot be known simultaneously
E) electrons that are filling in orbitals of equal energy will fill separate orbitals first
20)
How many unpaired electrons are there in a chromium atom?
A) 4
B) 6
C) 5
2
4
D) 0
E) 1
1
5
4 if you don’t know the exception to the rule (4s 3d ); 6 if you know that chromium is an exception (4s 3d )
21)
What is the electron configuration of calcium?
A) 1s22s22p23s23p24s2
B) 1s22s22p4
C) 1s22s22p63s23p5
D) 1s22s22p63s23p64s2
22)
23)
Which of the following shows the proper symbolism of an orbital diagram?
A) dots represent valence electrons
B) boxes represent orbitals; arrows represent electrons
C) dots represent electrons; lines represent bonds
D) boxes represent energy levels; arrows represent electrons
According to the Aufbau principle:
A) electrons will enter the 3d sublevel before they enter the 4s sublevel
B) electrons will fill the 2p sublevel before they fill the 2s orbital
C) electrons will fill the 4s sublevel before they fill the 3d sublevel
D) electrons will fill the 4f sublevel before they fill the 4d sublevel
24)
What is true of the electron configurations of the noble gases?
A) They are in column 18 because they have 18 valence electrons
B) They are in column 8 because they have 8 valence electrons
C) Their full s and p sublevels makes them very reactive
D) They would rather lose electrons than gain them
25)
26)
Each group number in the main block of the periodic table corresponds to _______
A) the number of valence electrons
B) an oxidation number
C) an energy sublevel
D) a principal energy level
Which element is an inner transition metal?
A) platinum
27)
C) astatine
D) uranium
Which of the following selections contains only transition metals?
A) Mg, Li, Cs
28)
B) copper
B) La, Ac, U
C) Mn, W, Ag
D) Si, Br, O
How does the general trend for electronegativity change from left to right across the periodic table?
A) It first decreases, then increases
B) It first increases, then decreases
C) It tends to increase
D) It tends to decrease
E) It does not change
29)
Why does atomic radius increase down a group in the periodic table?
A) The atomic number increases
B) There are more valence electrons
C) The number of principal energy levels increases
D) The oxidation number increases
E) The shielding effect does not bind the outer electrons as tightly to the nucleus
E) iron
30)
31)
2+
What are the main differences between Ca and Ca ?
2+
A) Ca loses two electrons and a valence energy level
2+
B) Ca gains two protons and has a smaller atomic radius
2+
C) Higher effective nuclear charge in Ca pulls the remaining electrons in closer
2+
D) Ca gains shielding
Why is the radius of an anion always greater than the radius of its neutral atom?
A) because atomic orbitals expand all by themselves
B) because the atom gains an energy level when electrons are gained
C) because of increased electron repulsion
D) anions have increased shielding
32)
33)
Which group of the periodic table has the highest ionization energy?
A) the alkali metals
B) the alkaline earth metals
C) the noble gases
D) the halogens
Which of the following elements has the largest atomic radius?
A) sodium
34)
D) chlorine
B) phosphorus
C) tungsten
D) strontium
Which of the following elements has the highest electronegativity?
A) oxygen
36)
C) aluminum
Which of the following elements has the largest ionization energy?
A) sulfur
35)
B) magnesium
B) fluorine
C) sulfur
D) chlorine
Why aren’t the noble gases diatomic in nature?
A) they make double bonds, not single bonds
B) they bond well to other elements, not to other atoms of the same element
C) they are stable with 8 valence electrons
D) they have an oxidation number of (-1).
37)
Put these elements in order of increasing atomic radius:
nitrogen, cobalt, mercury
A) nitrogen, cobalt, mercury
B) cobalt, mercury, nitrogen
C) cobalt, nitrogen, mercury
D) nitrogen, mercury, cobalt
38)
Which of the following will have the smallest atomic radius?
A) neon
39)
B) arsenic
C) vanadium
D) magnesium
Which of the following describes what takes place when oxygen is ionized?
A) a gain of two electrons
B) a loss of two electrons
C) a gain of two protons
D) a loss of two protons
Look at the graph above to answer questions 40-42
40)
What is the overall trend for the ionization energies of the noble gases?
A) They increase with the increase in atomic number
B) They decrease with the increase in atomic number
C) There is no trend that can be observed.
41)
Which of the following explains the highest spikes on the graph?
A) Noble gases lose electrons easily
B) Noble gases have the most nuclear pull (change from what was written on your version of this)
C) Noble gases have a high shielding effect
D) Noble gases are the largest elements on the periodic table
42)
Which elements are found in the lowest regions of the graph?
A) the alkali metals
B) the halogens
C) the chalcogens
D) the alkaline earth metals
43)
Which of the following is NOT a commonality among fluorine, chlorine, bromine, iodine, and astatine?
A) They all have 7 valence electrons
B) Their ending electron configuration is ns2np5
C) They have an oxidation number of -1
D) They are all diatomic nonmetals
E) They are all halogens
44)
Three elements, X, Y, and Z, have consecutive increasing atomic numbers. If element Z is a halogen, what will be the
charge for element X when it forms an ion?
A) -3
45)
B) +3
C) +1
D) -1
Nonmetals in the second period of the periodic table all tend to _____.
A) lose electrons to form a stable 1st energy level
B) lose electrons to form a stable 2nd energy level
C) gain electrons to form a stable 2nd energy level
D) lose electrons to form a stable 3rd energy level
E) gain electrons to form a stable 3rd energy level
46)
Which of the following is the electron configuration for copper?
A) 1s22s22p63s23p64s13d5
B) 1s22s22p63s23p64s23d9
C) 1s22s22p63s23p64s13d10
D) 1s22s22p63s23p64s23d7
(Cu is an exception; 4s13d10 is the exception; 4s23d9 is what would be predicted on the periodic table)
47)
Which of these elements contains two valence electrons?
A) helium
1s
48)
2s
49)
2p
C) carbon
3s
D) oxygen
3p
What element is represented by the orbital diagram above?
A) zinc
1s
B) sodium
2s
B) potassium
2p
C) argon
3s
D) chlorine
3p
Determine the quantum numbers of the circled electron above (in the order of n, l, ml, ms)
A) 2 ,0, 1, +1/2
B) 2, 2, 0, +1/2
C) 3, 1, 1, +1/2
D) 2, 1, 0, +1/2
E) neon