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1. List the properties of:
a. metals
Conductor of heat and electricity. Malleable,
which means that they can be hammered into very
thin sheets without breaking. Ductile, which means
that they can be drawn into wires. Fresh surface.
Solids at room temperature.
b. nonmetals
Poor conductor of heat and electricity. Brittle—
that they will shatter if struck with a hammer.
Solids are not lustrous. Can be solid, liquid, or
gas at room temperature depending upon the
elements
c. metalloids or semimetals
Intermediate between metals and nonmetals.
2. Who is Dmitri Mendeleev, and what was his contribution
to chemistry?
Russian chemist and teacher, published a periodic table
of the elements. His organization of elements was based
on atomic mass. Mendeleev’s periodic table made it
possible to predict properties of elements that had not
yet been discovered.
3. How is the modern periodic table different from the
first periodic table?
Mendeleev’s periodic table orders the elements
based on their atomic mass whereas Modern periodic
table orders the elements based on their atomic number.
Mendeleev’s periodic table has 8 vertical columns
calaed groups and 12 horizontal rows called periodic.
Modern periodic has 18 columns called groups and 7 rows
called periods. Mendeleev’s periodic table has
elements with dissimilar properties in the same groups
sometimes. Modern periodic table elements have similar
properties repeated at regular intervals.
4. What is the modern periodic law?
The periodic law states “when elements are arranged in
order of increasing atomic number, there is a periodic
repetition of their chemical and physical properties”
5. Organization of the periodic table. Indicate where the
following are located on the periodic table.
a. periods
Horizontal called periods.
b. groups
chemical properties appear at regular intervals,
within the vertical columns called groups.
c. Alkali metals
Group 1
d. Alkaline Earth Metals
Group 2
e. Halogens
Group 17
f. Noble Gases
Group 7
g. Representative or Main Grou
h.
Transition Metals
Group IIIA-IIB (new group 3-12)
i.
Inner Transition Metals
k. Lanthanides
l.
Actinides
89-103
m.
metals
n.
nonmetals
o.
metalloids
6. Indicate which elements on the periodic table are:
a. gases at room temperature.
Fluorine, oxygen, chlorine, nitrogen and hydrogen,
Radon, helium, xenon, neon, krypton and argon
b. liquids at room temperature.
Group one elements, Bromine and Mercury
7. Trends in the periodic table.
a. How does the size of the atom vary as you move left to
right across the periodic table? Why?
Atomic size decrease as you move left to right across a
period. because there are more protons and electrons,
which create greater attraction.
b. How does the size of the atom vary as you move down the
periodic table? Why?
The size increase, because increasing number of
electron shells. where the inner shells reduce the
attractive forces of the nucleus and repel the
electrons in the outer shell, decrease. Additional
electrons in elements with higher atomic numbers are
filling orbitals that have a larger average radius. The
size of atoms in determine by the size of the electron
distribution of the valence orbitals.
c. What is ionization energy?
Is the energy required to remove an electron form a
specific atom. It is measured in kj/mol.
d. How does the ionization energy vary as you move left to
right across the periodic table? Why?
The inoization energy for an atom increases, because
the more protons in the nucleaus, the stronger the
attraction of the nucleus to electrons.
e. How does the ionization energy vary as you move down
the periodic table? Why?
Ionization energy decreases as we go down a group,
because electron removed is farther from the nucleus as
the number of protons increases. Being farther away
from the positive attraction makes it easier for that
electron to be pulled off.
f. What is electron affinity?
Electron affinity is a measure of the energy released
when an extra electron is added to an atom. Electron
affinities are measured in the gaseous state.
g. How does electron affinity vary as you move left to
right across the periodic table? Why?
Electron affinities increase (more negative).
h. How does electron affinity vary as you move down the
periodic table? Why?
Electron affinity decrease
i. What is electronegativity?
Electronegativity is a measure of the ability of an
atom to attract the electrons when the atom is part of
a compound.
j. How does electronegativity vary as you move left to
right across the periodic table?
Increase
k. How does electronegativity vary as you move down the
periodic table?
Decrease