Organization of the PTable
Classification of Elements
Periodic Trends
Refreshers
Miscellaneous
100
Which Group 15 element is classified as a metalloid?
A) N
B) P
C) As
D) Bi
C) As
100
Which element is classified as a nonmetal?
A) Be
B) Al
C) Si
D) Cl
D) Cl
100
As the first five elements in Group 15 are considered in order of increasing atomic number, first ionization energy
A) decreases
B) increases
C) decreases, then increases
D) increases, then decreases
A) decreases
100
When an atom of lithium loses an electron, the atom becomes a
A) negative ion with a radius smaller than the radius of the atom
B) negative ion with a radius larger than the radius of the atom
C) positive ion with a radius smaller than the radius of the atom
D) positive ion with a radius larger than the radius of the atom
C) positive ion with a radius smaller than the radius of the atom
100
Draw a Lewis electron-dot diagram for Oxygen
Oxygen has 6 valence electrons.
200
D) number of protons
200
The Group 1 elements below hydrogen are called alkali metals, and the first five Group 17 elements are called halogens.
Explain, in terms of electrons, why the halogens are all placed in the same group on the Periodic Table.
— All halogen atoms have 7 valence electrons in the ground state.
200
Bromine, chlorine, fluorine, and iodine are four elements in Group 17 that can be differentiated by some of their properties.
State the trend in atomic radius for these four elements as they are considered in order of increasing atomic number.
As atomic number increases, atomic radius increases.
200
Compare the energy of an electron in the first shell of a silicon atom to the energy of an electron in the third shell of the same atom.
An electron in the first shell of an atom of silicon has less energy than an electron in the third shell.
200
Which element requires the most amount of energy to remove the most loosely held electron from a gaseous atom in the ground state?
A) Na
B) Ar
C) P
D) Cl
B) Ar
300
Which element has chemical properties most similar to sodium? Explain why!
A) magnesium
B) oxygen
C) phosphorus
D) rubidium
D) rubidium
Reasoning: same number of valence electrons!
300
Which list of elements includes a metal, a metalloid, and a noble gas?
A) Rb, Cl, Ne
B) Sr, Si, Rn
C) Rn, Cl, Ne
D) Si, Rb, Sr
B) Sr, Si, Rn
300
State, in terms of electrons, why the radius of a Be2+ ion is smaller than the radius of a Be atom.
Possible answers:
— A Be2+ ion is smaller because it has only 1 shell of electrons and a Be atom has 2 shells of electrons.
— The Be atom has 4 electrons and the Be2+ ion has 2 electrons.
— A Be2+ ion forms when the Be atom loses 2 electrons.
— A beryllium ion has two fewer electrons.
300
What is the net charge on an ion that has 9 protons, 11 neutrons, and 10 electrons?
1-
300
What can be concluded if an ion of an element is bigger than an atom of the same element?
A) The ion is negatively charged because it has fewer electrons than the atom.
B) The ion is negatively charged because it has more electrons than the atom.
C) The ion is positively charged because it has fewer electrons than the atom.
D) The ion is positively charged because it has more electrons than the atom.
B) The ion is negatively charged because it has more electrons than the atom.
400
State, in terms of protons, why tennessine is listed before oganesson in Period 7 on the Periodic Table of the Elements.
Possible answers include:
— Atoms of tennessine have 117 protons and atoms of oganesson have 118 protons.
— Elements on the Periodic Table of the Elements are arranged in order of increasing atomic number, which is the number of protons in their atoms.
400
Which elements are malleable and good conductors of electricity? Explain why!
A) iodine and silver
B) iodine and xenon
C) tin and silver
D) tin and xenon
C) tin and silver
Reasoning: metals!
400
As the atomic number increases in Group 2 from Be to Ba, the first ionization energy
A) decreases, and the atomic radius decreases
B) decreases, and the atomic radius increases
C) increases, and the atomic radius decreases
D) increases, and the atomic radius increases
B) decreases, and the atomic radius increases
400
Compare...
1) number of electrons
2) radius
Phosphorus atom vs. P3– ion
P3– ion has more electrons and a larger radius
400
Which statement explains why a xenon atom is electrically neutral?
A) The atom has fewer neutrons than electrons.
B) The atom has more protons than electrons.
C) The atom has the same number of neutrons and electrons.
D) The atom has the same number of protons and electrons.
D) The atom has the same number of protons and electrons.
500
An element that is a very reactive metal could have an atomic number of
A) 9
B) 2
C) 19
D) 79
C) 19
500
Compare the electrical conductivity of an alkali metal at standard temperature and pressure with the electrical conductivity of a halogen.
Metals conduct electricity better than halogens.
500
Several elements are considered endangered because there is a risk of these elements becoming unavailable for commercial uses in the next 100 years. Helium, zinc, gallium, indium, and tellurium are included in the list of these endangered elements.
Explain, in terms of electron shells, why the atomic radius of an atom of indium is greater than the atomic radius of an atom of gallium when both atoms are in the ground state.
Indium atoms have 5 shells of electrons; gallium atoms have only 4 shells of electrons.
500
State, in terms of electrons, why the ionic radius of a Group 17 element is larger than the atomic radius for the same element.
The valence electron shell of a Group 17 atom gains an electron when the atom becomes an ion.
500
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