Metallic Character
The ability of an atom to donate electrons and form
positive ion (cation) is
known as electropositivity or metallic character. Down
the group, metallic
character increases due to increase in atomic size and
across the period, from left to right electropositivity decreases due to
decrease in atomic size.
Non-Metallic Character
The ability of an atom to accept electrons to form a
negative ion (anion) is
called non-metallic character or electronegativity. The
elements having high
electro-negativity have a higher tendency to gain
electrons and form anion.
Down the group, electronegativity decreases due to
increase in atomic size and
across the period, from left to right electronegativity
increases due to decrease
in atomic size.
(i). Which of the following correctly represents the
decreasing order of metallic
character of
Alkali metals plotted in the graph?
a)
Cs>Rb>Li>Na>K
b)
K>Rb>Li>Na>Cs
c)
Cs>Rb>K>Na>Li
d) Cs>K>Rb>Na>Li
(ii). Hydrogen is placed along with Alkali metals in the
modern periodic table
though it
shows non-metallic character
a) as Hydrogen
has one electron & readily loses electron to form negative
ion
b) as Hydrogen
can easily lose one electron like alkali metals to form
positive ion
c) as Hydrogen
can gain one electron easily like Halogens to form
negative ion
d) as Hydrogen
shows the properties of non-metals
(iii). Which of the following has highest
electronegativity?
a) F
b) Cl
c) Br
d) I
(iv). Identify the reason for the gradual change in
electronegativity in halogens
down the
group.
a)
Electronegativity increases down the group due to decrease in atomic
size
b)
Electronegativity decreases down the group due to decrease in
tendency to
lose electrons
c)
Electronegativity decreases down the group due to increase in atomic
radius/
tendency to gain electron decreases
d)
Electronegativity increases down the group due to increase in forces of
attractions
between nucleus & valence electrons
(v). Which of the following reason correctly justifies that
“Fluorine (72pm) has
smaller atomic
radius than Lithium (152pm)”?
a) F and Li are
in the same group. Atomic size increases down the group
b) F and Li are
in the same period. Atomic size increases across the
period due to
increase in number of shells
c) F and Li are
in the same group. Atomic size decreases down the group
d) F and Li are
in the same period and across the period atomic size/radius
decreases from
left to right.
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