chem Flashcards
made up of very small particles (atoms/molecules) that are
in constant motion and are held together by attractive forces.
Matter
low KE
solid
very high KE
gas
loosely packed together
liquid
high density
solid
Their kinetic energy is just enough for
them to vibrate and rotate in their fixed
positions
solid
A gaseous mixture of positive ions and
electrons
plasma
Heat energy is converted
to KE and the particles
vibrate and rotate faster
about their fixed
positions
melting
When the temperature is
low, the particles no
longer have enough energy
to move freely
freezing
occurs when
some particles of the
liquid have acquired
enough energy to break
away from their
attraction to the other
particles and escape as
gas.
evaporation
When gas is adequately
cooled, it changes into
a liquid.
condensation
When particles at the surface of a
solid acquire enough energy to
break away from the forces of
attraction in the solid, they escape
as gas.
sublimation
Occurs when the particles
of a gas condense
directly into a solid
without going through the
liquid state.
deposition
He proposed that if you kept cutting a
substance in half forever. Eventually you would end up with an
“uncuttable” particle.
Democritus
called the particles “atomos” meaning “indivisible” in
Greek
Democritus
revived
Democritus’s early ideas about the atom
John Dalton
“father of the modern atomic theory”
Dalton
discovered electrons
J.J Thomson
first subatomic particles to be identified
electrons
proposed the plum pudding model of the atom
Thomson
discovered nucleus
Ernest Rutherford
all the positive charge of an
atom is concentrated in a small central area.
nucleus
suggested that electrons travel around the
nucleus in definite paths
Niels Bohr
stated that electrons do not move in set
paths around the nucleus, but in waves
Erwin Schrodinger
clouds of probability
orbitals
The lightest of all three subatomic
particles. In fact, it is so light that it
has no great effect on the mass of
the atom
electron
It carries a net charge of negative
one (-1)
electron
Carries one positive electric
charge (+1)
proton
what subatomic particle was the first to observe by Eugene
Goldstein
proton
Has no net electrical charge
neutron
how to get neutron?
subtract mass number to atomic number
In the periodic table, high energy = ?
period
In the periodic table, valence electron = ?
group
region of space around the nucleus where the electron is most likely to be found
atomic orbitals
refers to the assignment of all the electrons in an atom into specific shells (energy levels) and subshells (sublevels)
Electron Configuration
known as “building-up” principle, states that electron’s occupy orbitals in order of increasing energy
Aufbau Principle
only 2 electrons can occupy each orbital and there must have opposite spins
Pauli’s Exclusion Principle
electrons will half-fill each of the available equivalent orbitals before filling the second half of each orbital
Hund’s Rule
(True or False) Does the energy increases as the distance of the orbit from the nucleus decreases?
false
The orbits also known as shells or ?
energy levels
If electron received extra energy, it can jump into a higher energy level, this is also called ?
excited state
The electron in the excited state can return to its original lower energy level or _____ by releasing discreet amount of energy in the form of light
ground state
The probability of finding the electrons is greatest at a certain specified distances from the nucleus called?
energy levels (electron shells)
a quantitative measurement of the
energy change when an electron is added to a neutral gaseous
atom.
electron affinity
(true or false) A more negative electron affinity value indicates higher
affinity?
true
(true or false) The trend of the electron
affinity increases from left to
right and bottom to top throughout the periodic
table?
true
Why is the trend of the electron
affinity increases from left to
right throughout the periodic
table?
due to a nuclear change
because of the attraction of the
electrons to the nucleus
Why is the trend of the electron
affinity increases from bottom to
top throughout the periodic
table?
due to the atomic
size.
used to find out if an atom or molecule will
be an electron acceptor or an electron donor and if a pair of
reactants will participate in charge transfer reaction
electron affinity
the ability of an atom to lose electrons and become positive ions.
metallic character
the tendency of an element to easily accept electrons and form
negative ions or anions.
nonmetallic character
known as donors, (donates electrons and from positive ions)
metallic character
known as acceptors, (accepts electrons and forms negative ions)
nonmetallic character
true or false. When ionization energy increases, it requires more energy to lose valence
electrons.
true
true or false. Non metals have high ionization energy and metals have low
ionization energy.
true
directly proportional to non
metallic character and
indirectly proportional to
metallic character
ionization energy/electronegativity
Tendency of an atom or a functional group to attract electrons toward itself
electronegativity
true or false. As the atomic radius increases, so does a metal’s ability to lose electorns because of
distance.
This makes them directly proportional. While it is indirectly proportional to non metallic
character
true
In the periodic table, trend of metallic character?
increases from top right to bottom left
In the periodic table, trend of nonmetallic character?
increases from bottom left to top right
a process that
involves the removal of electrons
present in an orbit outside the
atom.
Ionization
the minimum energy required to
remove a loosely bound electron of an atom in the
gaseous state. It measures the capability of an atom to
lose an electron during a chemical reaction. It is opposite
to electron affinity
Ionization energy
It would take energy for the positively charged nucleus
to attract the negatively charged electrons and to
completely remove an electron from the outermost shell
from a neutral atom
Ionization energy
Since energy is added to the system, the process is
endothermic, and the ionization values are positive. True or false?
True
Is Ionization energy is ALWAYS POSITIVE?
True
Since only one electron is removed, the
ionization energy is also known as the _______
first ionization energy
The farther away an electron is from
the nucleus, the easier it is to pull it
away. TRUE OR FALSE
true
The larger the effective nuclear charge,
the less energy it takes to release an
electron
false
Ionization energy, electronegativity and electron affinity has same trend in periodic table?
Yes
Non metals have high electronegativity, making it easier to attract electrons. TRUE OR FALSE
true
a measure of how strongly an atom attracts
the shared electrons in a chemical bond.
Electronegativity
The concept of electronegativity was first introduced by Linus
Pauling and is commonly measured using ______ with values ranging from approximately 0.7 to 4.0.
Pauling scale
How electronegativity works?
The greater the electronegativity of an atom the
stronger its ability to attract shared electron.
Why are noble gases not included in electronegativity?
Noble gases (Group 18) are not included in discussions of electronegativity trends because they typically do not form chemical bonds due to their stable electronic configurations. As such, they have no tendency to attract additional electrons and thus have extremely low electronegativity values.
The most electronegative element is ________, with a Pauling electronegativity value of 3.98,
while the least electronegative elements are typically found among the alkali metals, such as
_______, with a value of approximately 0.7.
Flourine, Cesium
