The Periodic Table
Regents Review
2. The first ionization energy of an element is 736 kJ per mole
of atoms. How many valence electrons does an atom of this
element in the ground state have?
A) 1
B) 2
C) 3
D) 4
• Correct Answer: Option B - 2
• The element having the first ionization energy of, 736 kJ/mol is
Magnesium.
3. Which element in Group 15 has the strongest metallic
character?
A) As
B) P
C) N
D) Bi
• Correct Answer: Option D - Bi
• From left to right across the period, metallic character
decreases. But it increases going down a group (last element
in a group will have the most metallic character). Bi is the last
element in group 15 so it is the most metallic. Order of group
15 elements in descending rate of metallic character is:
Bi(Bismuth), Sb(Antimony), As(Arsenic), P(Phosphorus) and
N(Nitrogen).
4. Which compound forms a colored aqueous solution?
A) CaCl22
B) CrCl3
C) NaOH
D) KBr
• Correct Answer: Option B - CrCl3
• Colored aqueous solutions are a characteristic of transition
compounds. The only transition compound in the above
choices is CrCl3. Cr is a transition element.
5. Which element has the highest first ionization energy?
A) Sodium
B) Phosphorus
C) Aluminum
D) Calcium
• Correct Answer: Option B: Phosphorus
• The energy needed to remove one or more electrons from a
neutral atom to form a positively charged ion is a physical
property that influences the chemical behavior of the atom.
By definition, the first ionization energy of an element is the
energy needed to remove the outermost or highest energy,
electron from a neutral atom in the gas phase
6. Which of the following elements has the smallest atomic radius?
A) Nickel
B) Cobalt
C) Potassium
D) Calcium
• Correct Answer: Option A - Nickel
• Atomic radius is called the width of an atom, but it is not a
precisely defined physical quantity, nor is it constant in all
circumstances. Atomic Radius gets greater down the periodic table
and gets smaller to the right in the periodic table. Going from left
to right across the periodic table, the number of protons increases.
The more they increase, the more they pull and attract the outer
electrons from the outermost electron shell, making the atomic
radius smaller.
7. Which set of elements contains a metalloid?
A) Li, Mg, Ca, Kr
B) Ba, Ag, Sn, Xe
C) K, Mn, As, Ar
D) Fr, F, O, Rn
• Correct Answer: Option C - K, Mn, As, Ar
• The metalloids are elements which have intermediate
properties and cannot be classified as either metals or
nonmetals. They are also referred to as semimetals.
• In the Periodic Table, the location of the stepped line divides
metals and nonmetals. Elements next to the left or right of
this line are metalloids. This clearly lists Aresenic as a
metalloid which is a part of option C.
8. An atom of which of the following elements has the greatest
ability to attract electrons?
A) Chlorine
B) Silicon
C) Sulfur
D) Nitrogen
• Correct Answer: Option A - Chlorine
• Electronegativity is a chemical property that describes the ability
of an atom to attract electrons towards itself in a covalent bond.
10. Atoms of elements in a group on the Periodic Table have
similar chemical properties. This similarity is most closely
related which characteristic of the atoms?
A) Number of principal energy levels
B) Atomic numbers
C) Number of valence electrons
D) Atomic masses
• Correct Answer: Option C - Number of valence electrons
• Most of the time elements in the same group have the same
number of valence electrons. Valence electrons are involved in
bonding and this effects how elements react and determines
their chemical properties.
11. Most of the groups in the Periodic Table of the elements contain:
A) Nonmetals only
B) Nonmetals and metals
C) Metals only
D) Metals and metalloids
• Correct Answer: Option C - Metals only
• One reason the periodic table of the elements is so useful is because it is
a means of arranging elements according to their similar properties.
There are multiple ways of grouping the elements, but they are
commonly divided into metals, semimetals, and nonmetals. Most
elements are metals. There are so many metals, they are divided into
groups: alkali metals, alkaline earth metals, and transition metals. The
transition metals can be divided into smaller groups, such as the
lanthanides and actinides.
12. In Period 2 of the Periodic Table, which Group contains the
element with the highest first ionization energy?
A)
B)
C)
D)
Alkali metals
Noble gases
Alkaline earth metals
Halogens
• Correct Answer: Option B - Noble gases
13. The elements in Period 3 all contain the same number of
A) Protons
B) Valence electrons
C) Occupied principal energy levels
D) Neutrons
• Correct Answer: Option C - Occupied principal energy levels
• A period 3 element is one of the chemical elements in the third row
(or period) of the periodic table of the chemical elements. The
periodic table is laid out in rows to illustrate recurring (periodic)
trends in the chemical behavior of the elements as their atomic
number increases: a new row is begun when chemical behavior
begins to repeat, meaning that elements with similar behavior fall
into the same vertical columns
14. Compared to atoms of metals, atoms of nonmetals
generally
A) Have lower first ionization energies
B) Conduct electricity more readily
C) Have higher electronegativities
D) Lose electrons more readily
• Correct Answer: Option C - Have higher electronegativities
• Electronegativity is a chemical property that describes the
ability of an atom to attract electrons towards itself in a
covalent bond.
• Atoms of metals have higher first ionization energies, conduct
electricity more readily and also lose electrons more readily
16. When a metal atom combines with a nonmetal atom, the
nonmetal atom will
A) Lose electrons and decrease in size
B) Gain electrons and increase in size
C) Lose electrons and increase in size
D) Gain electrons and decrease in size
• Correct Answer Number: B - Gain electrons and increase in size
• Metals are Electropositive Elements. Metals are very reactive.
Metals tend to loose electrons easily and form positively charged
ions; therefore metals are called electropositive elements. Sodium
metal forms sodium ions Na+, Mg forms positively charged
Magnesium ions Mg2+ and aluminium forms aluminium ions Al3+.
The electropositive nature allows metals to form compounds with
other elements easily
17. Which halogens are gases at standard temperature and
pressure?
A) Iodine and fluorine
B) Chlorine and bromine
C) Chlorine and fluorine
D) Iodine and bromine
• Correct Answer: Option C - Chlorine and fluorine
18. As the elements of Group 17 are considered in order of
increasing atomic number, there is an increase in:
A) First ionization energy
B) Number of electrons in the first shell
C) Electronegativity
D) Atomic radius
• Correct Answer: Option D - Atomic radius
19. At STP, which substance is the best conductor of electricity?
A) Silver
B) Nitrogen
C) Sulfur
D) Neon
• Correct Answer: Option A - Silver
20. Which two characteristics are associated with metals?
A) Low first ionization energy and low electronegativity
B) High first ionization energy and low electronegativity
C) High first ionization energy and high electronegativity
D) Low first ionization energy and high electronegativity
• Correct Answer: Option A - Low first ionization energy and
low electronegativity
23. Which group on the Periodic Table contains elements that react
with oxygen to form compounds with the general formula X2O?
A) Group 14
B) Group 1
C) Group 2
D) Group 18
• Correct Answer: Option B - Group 1
• Elements of group 1 are Hydrogen (H), Lithium (Li), Sodium (Na),
Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr). All these
elements have 1 valence electron available for reaction. Oxygen has
6 valence electrons which requires 2 additional electrons for
completing the last subshell. Hence, oxygen reacts with 2 atoms of
each of the group 1 elements to form a compound X2O.
24. In the ground state, each atom of an element has two valence
electrons. This element has lower first ionization energy than calcium.
Where is this element located on the Periodic Table?
A) Group 1, Period 4
B) Group 2, Period 3
C) Group 3, Period 4
D) Group 2, Period 5
• Correct Answer: Option D - Group 2, Period 5
• Valence electrons in each of the group in a periodic table is related to
the group to which an element belongs to; i.e. elements in group 1
have 1 valence electron, elements in group 2 have 2 valence electrons,
etc.
• Hence, the element mentioned above has to be in group 2.
• Also the first ionization energy reduces as you go down a group.
Calcium lies in period 4. Hence, the element being referred in the
question is in period 5.
• The element referred to is Strontium (Sr).
26. As the atoms of the elements in Group 1 of the Periodic Table are
considered from top to bottom, the number of valence electrons in the
atoms of each successive element
A) Increases
B) Decreases
C) Remains the same
D) Reduces to zero
• Correct Answer: Option C - Remains the same
• The valence electrons are the electrons in the last shell or energy level of an
atom. They do show a repeating or periodic pattern. The valence electrons
increase in number as you go across a period. Then when you start the new
period, the number drops back down to one and starts increasing again.
• For example, when you go across the table from carbon to nitrogen to
oxygen, the number of valence electrons increases from 4 to 5 to 6. As we
go from fluorine to neon to sodium, the number of valence electrons
increases from 7 to 8 and then drops down to 1 when we start the new
period with sodium. Within a group--starting with carbon and going down
to silicon and germanium--the number of valence electrons stays the same.
28. How do the atomic radius and metallic properties of
sodium compare to the atomic radius and metallic properties
of phosphorus?
A)
B)
C)
D)
Sodium has a larger atomic radius and is more metallic.
Sodium has a larger atomic radius and is less metallic.
Sodium has a smaller atomic radius and is more metallic.
Sodium has a smaller atomic radius and is less metallic.
• Correct Answer: Option A- Sodium has a larger atomic radius
and is more metallic.
30. What is the total charge of the nucleus of a carbon atom?
A) -6
B) +6
C) 0
D) +10
• Correct Answer: Option B - +6
• Every carbon atom contains six positively charged particles
called protons in its nucleus and six or more neutral particles
called neutrons. The carbon atom's nucleus is surrounded by
six negatively charged electrons
• Same Group so same number of valance electrons thus they
have similar properties