Element Trends And Properties Flashcards
What is the atomic radius
Atomic radius is half of the distance between the nuclei of two atoms of the same element that are bonded together.
Rank the following elements in order from smaller to largest atomic radius.
Carbon, aluminum, oxygen, potassium
Oxygen, sulfur, fluorine
Sodium, beryllium, magnesium
Oxygen<Carbon<Aluminum<Potassium
Fluorine<Oxygen<Sulfur
Beryllium<Magnesium<Sodium
Does atomic radius increase or decrease down a group on the periodic table? What causes this trend?
Atomic radius increases when you move down a group in the periodic table. This happens because valence electrons are a higher energy level that is further away from the nucleus.
Does atomic radius increase or decrease going from left to right in the periodic table?
Atomic radius decreases as you move left to right on the periodic table
Which atom in each pair has the largest atomic radius
Mg or Ca
S or O
O or F
Ca
S
O
What is ionization energy?
Ionization energy is the energy required to remove an electron from an atom.
Does ionization energy increase or decrease down a group (top to bottom) on the periodic table? What causes this trend?
Ionization energy decreases down a group on the periodic table. This happens because the attraction from the nucleus increases and the electron decreases as the distance of those electron coming from the nucleus increase.
Does Ionization energy increase or decrease moving left to right on the period table?
Ionization energy increases as the elements move from the left to the right.
Why does Fluorine have a higher ionization energy than Iodine?
This is because as the elements move down on the periodic table by groups the ionization energy decreases. Fluorine and Iodine are in the same group but, fluorine is further down. This means that Fluorine has a higher ionization energy.
Rank the following in order from lowest to highest ionization energy.
Helium, Chlorine, Aluminum, Cesium
Cesium (55), Aluminum (13), Chlorine (17), Helium (2)
What is electronegativity?
Electronegativity is the ability of an atom that is in a molecule that attracts electrons to itself.
Does electronegativity increase or decrease from left to right across a period? What causes this trend?
Electronegativity increases moving left to right on the periodic table, this however is not applied to the noble gases. Electronegativity typically decreases moving down on the periodic table by groups.
Why is Fluorine more electronegative than Iodine?
Fluorine is more electronegative than Iodine because of their location. Fluorine is in the same group as Iodine, however Fluorine is located higher up in the group which makes Fluorine more electronegative.
Which atom in the pair is more active?
k or zn
au or ag
cl or f
o or n
K
Au
F
O
Does atomic radius increase of decrease from left to right across the periodic table?
Decrease
Why does the atomic radius decrease as you move from left to right across the periodic table?
The increasing number of protons (effective nuclear charge) draws the electrons closer to the nucleus
Does atomic radius increase or decrease as you move down a group in the periodic table?
Valence electrons are in higher energy levels farther from the nucleus.
Are cations smaller or larger than their parent atoms?
Smaller
Why are cations smaller than their parent atoms?
The formation of a cation removes electrons from the outermost energy level.
Are anions smaller or larger than their parent atoms?
Larger
Why are anions larger than their parent atoms?
The addition of electrons to the outer energy level results in the electrons repelling each other and spreading apart. Since the number of protons stays the same, but the number of electrons increases, the pull from the nucleus on each electron is less (like a tug of war).
Referring to a periodic table, arrange the following atoms in order of increasing size.
O,S, F
Na, Be, Mg
F, O, S
Be, Mg, Na
Which is larger?
Fr, F
Kr, Xe
Mg, K
Si, P
O, P
Na, Cl
Cl, Cl-
Na, Na+
Fe+2, Fe+3
Fr
Xe
K
Si
P
Na
Cl-
Na
Fe+2
1st Ionization Energy
minimum energy required to remove the first electron from the ground state of an isolated gaseous atom or ion
2nd Ionization Energy
minimum energy required to remove the second electron from the ground state of an isolated gaseous atom or ion
3rd Ionization Energy
minimum energy required to remove the third electron from the ground state of an isolated gaseous atom or ion
Does ionization energy generally increase or decrease moving from left to right across the periodic table?
Generally increases
Why does ionization energy generally increase moving from left to right across the periodic table?
The attraction from the nucleus increases and the electrons are closer to the nucleus
Does ionization increase or decrease moving across down a group in the periodic table?
Decreases
Why does ionization energy decrease moving down a group in the periodic table?
The attraction between the nucleus and the electrons decreases as the distance of the electrons from the nucleus increases.
Why is there a significant increase in the 3rd and 4th ionization energy for Aluminum?
More energy is used to remove the inner shell of an electron.
Explain the drastic increase in the first ionization energy of SIlicon and Phosphorus.
Phosphorus has more valence electrons therefore it takes more ionization energy to remove electrons.
Which of the following has the greatest first ionization energy?
S, Cl, Se, Br
B, Al, C, Si
Cl
C
Choose the atom in each pair that has the LOWER first ionization energy:
Al, B
O, C
K, Ca
C, N
Na, K
Ar, K
Sn, Br
B, C
Al
C
K
C
K
K
Sn
B
Electronegativity
The ability of an atom in a molecule to attract electrons to itself
Does electronegativity generally increase or decrease moving from left to right across the periodic table? What is the exception?
Increases; The exception is that electronegativity does not apply to noble gases
Why does electronegativity generally increase moving from left to right across the periodic table?
The pull from the nucleus increases and the ease with which atoms will gain an electron increases.
Does electronegativity generally increase or decrease moving down a group in the periodic table?
Decreases
Why does electronegativity generally decrease moving down a group in the periodic table?
The pull form the nucleus decreases.
What elements are the most electronegative?
Halogens are the most electronegative.
What elements are the least electronegative?
The noble gases are the least electronegative.
Metallic character
Metals are substances with low ionization energies because they willingly give up electrons to form cations. Nonmetals have high ionization energies because they DO NOT want to let go of their electrons. Nonmetals do have high electron affinities (ease at which atoms gain electrons) and high electronegativities, which is why they attract electrons from other atoms to form anions. Metals have low electron affinities and electronegativities because they do not want any electrons.
What are metals?
Substances with low ionization energies, because they willingly give up electrons to form cations
Do nonmetals have high ionization energies? Why or why not?
Yes, nonmetals have high ionization energies because they DO NOT want to let go of their electrons.
Do nonmetals have high or low electron affinities and electronegativities?
Nonmetals have high electron affinities and high electronegativities, which is why they attract electrons from other atoms to form anions.
Electron affnitities
The ease at which atoms gain electrons
Do metals have high or low electron affinities and electronegativities?
Metals have low electron affinities and electronegativities because they do not want any electrons
Metallic character does what as moving from left to right across the periodic table? Why?
Metallic character decreases moving left to right on the table. This happens because of the trend of electronegativity, ionization energy, and electron affinity.
How does metallic character move going down on the periodic table? Why?
Metallic character increases moving down on the periodic table. This is due to the trends of electronegativity, ionization energy, and electron affinity.
What metal is most active?
What nonmetal is most active
Francium
Fluorine
Choose the larger atom by atomic size
Ar or Ne
B or C
N or P
Cl or F
Ca or Sc
K or Br
Ar
B
P
Cl
Ca
K
Arrange these lists in order of increasing atomic radius
O,S,F
Li, O, C, F
Mg, Cl, Na, P
Na, Be, Mg
Br, At, F, I, Cl
Ca, Be, Ba, Sr
F, O, S
F, O, C, Li
Cl, P, Mg, Na
Be, Mg, Na
F, Cl, Br, I, At
Be, Ca, Sr, Ba
Which is the largest according to ionic size
Li or Li+
N3- or As3-
Cl or Cl-
Mg or Mg2+
In3+ or Rb1+
S or S2-
P3- or Cl-
K+ or Li+
Li
As3-
Cl-
Mg
Rb1+
S2-
P3-
K+
Put in order of decreasing atomic radius
As, As3+, As3-, As5+
As3-, As, As3+, As5+
Cl- means
adding one electron
What feature of the electron configuration will cause a large increase in the first ionization energy?
If an electron is full then there will be a large increase in the first ionization energy. This is because the fuller the electron, the harder to take anything away or out.
Which elements tend to have the higher first ionization energy?
Nonmetals
Choose the atom with the largest first ionization energy
B or F
O or S
N or P
S or Cl
Rb or Cs
Ga or Ge
F
O
N
Cl
Rb
Ge
Write the element with the highest Electronegativity
Na, Al, P, S
O, S, Se, Te
Li, Be, Mg, Na
P, S, As, Se
Sulfur
Oxygen
Beryllium
Sulfur
element with the highest electronegativity
Na or Cl
C or O
Cl or H
Na or H
Fe or O
Cl
O
Cl
H
O
Chemical activity: circle the more active element
K or Cs
K or Zn
Ba or Mg
Mg or Au
F or Cl
Ag or Au
Se or O
Cl or I
Cs
K
Ba
Mg
F
Au
O
Cl
