Part 1: Comprehension Passage
Read the following passage carefully and use it to answer the questions that follow.
Meet the Halogen Family
The halogens are a unique group of nonmetal elements
found in Group 17 of the periodic table. The name
"halogen" means "salt-former," and all elements in this
group are very reactive. They are so reactive that they are
never found alone in nature; they are always bonded to
other elements in compounds.
The first three members of the halogen family are Fluorine
(F), Chlorine (Cl), and Bromine (Br). What makes them a
family? The key lies in their atomic structure.
All elements in the same group have the same number of electrons in their outermost shell, also
known as the valence shell. For Group 17 elements, this number is 7. Let's see what this looks like for
each atom:
● Fluorine (Atomic Number 9) has 9 protons and 9
electrons. Its electron arrangement is 2,7. This
means the first shell is full with 2 electrons, and the
second shell has 7 electrons.
● Chlorine (Atomic Number 17) has 17 protons and
17 electrons. Its electron arrangement is 2,8,7. The
first two shells are full, and the third shell has 7
electrons.
● Bromine (Atomic Number 35) has 35 protons and
35 electrons. Its electron arrangement is 2,8,18,7.
The inner shells are full, and the outermost shell
has 7 electrons.
Having 7 valence electrons makes these atoms "eager" to gain 1
more electron to achieve a full outer shell, which is a stable
arrangement. This tendency to gain one electron is what makes
them so reactive. When they gain an electron, they become
negatively charged ions called anions.
As we move down the group from Fluorine to Chlorine to Bromine,
the number of protons and electron shells increases. The increasing
number of shells means the outermost electrons are farther from
the nucleus. This makes it harder for the larger atoms to attract an
extra electron, so reactivity decreases down the group. This is why
Fluorine is the most reactive halogen of all.
Read the following passage carefully and use it to answer the questions that follow.
Meet the Halogen Family
The halogens are a unique group of nonmetal elements
found in Group 17 of the periodic table. The name
"halogen" means "salt-former," and all elements in this
group are very reactive. They are so reactive that they are
never found alone in nature; they are always bonded to
other elements in compounds.
The first three members of the halogen family are Fluorine
(F), Chlorine (Cl), and Bromine (Br). What makes them a
family? The key lies in their atomic structure.
All elements in the same group have the same number of electrons in their outermost shell, also
known as the valence shell. For Group 17 elements, this number is 7. Let's see what this looks like for
each atom:
● Fluorine (Atomic Number 9) has 9 protons and 9
electrons. Its electron arrangement is 2,7. This
means the first shell is full with 2 electrons, and the
second shell has 7 electrons.
● Chlorine (Atomic Number 17) has 17 protons and
17 electrons. Its electron arrangement is 2,8,7. The
first two shells are full, and the third shell has 7
electrons.
● Bromine (Atomic Number 35) has 35 protons and
35 electrons. Its electron arrangement is 2,8,18,7.
The inner shells are full, and the outermost shell
has 7 electrons.
Having 7 valence electrons makes these atoms "eager" to gain 1
more electron to achieve a full outer shell, which is a stable
arrangement. This tendency to gain one electron is what makes
them so reactive. When they gain an electron, they become
negatively charged ions called anions.
As we move down the group from Fluorine to Chlorine to Bromine,
the number of protons and electron shells increases. The increasing
number of shells means the outermost electrons are farther from
the nucleus. This makes it harder for the larger atoms to attract an
extra electron, so reactivity decreases down the group. This is why
Fluorine is the most reactive halogen of all.
