Name
Period
Date
Practice: Predicting Relative Properties
Use your periodic table and references to determine these answers. DON’T look up actual numbers, but predict the largest or
smallest based on an elements position in the periodic table. The primary reference to use is The Periodic Table: Electron
Shells Affect Trends.
1.
For each set of atoms tell which atom has the biggest atomic radius:
Largest?
Lithium
Calcium
Krypton
Polonium
2.
Carbon
Beryllium
Zinc
Sulfur
Nitrogen
Radium
Calcium
Oxygen
Fluorine
Magnesium
Bromine
Tellurium
➜
➜
➜
➜
Li
Ra
Ca
Po
For each set of atoms tell which atom has the highest electronegativity
Highest EN?
Chlorine
Boron
Nitrogen
Lithium
Sulfur
Indium
Oxygen
Calcium
Aluminum
Aluminum
Fluorine
Francium
Magnesium
Gallium
Calcium
Silicon
➜
➜
➜
➜
Cl
B
F
Si
3. For each set of atoms tell which atom has the lowest ionization energy
Lowest IE?
Nitrogen
Iodine
Lithium
Aluminum
Fluorine
Bromine
Beryllium
Silicon
Oxygen
Fluorine
Boron
Phosphorus
Carbon
Chlorine
Carbon
Sulfur
➜
➜
➜
➜
C
I
Li
Al
4. Which would be larger the ionic radius or the atomic radius?
a. Calcium’s Atomic Radius or its Ionic Radius?
Calcium’s atomic radius would be larger because it loses an entire shell when it makes a +2 ion
b. Fluorine’s Atomic Radius or its Ionic Radius
Fluorine’s ion is larger because it has gained an electron and stuffed into an existing shell to make F–1
c. Bromine’s Atomic Radius or its Ionic Radius
The ion is larger (it has gained an electron) to make Br–1
d. Potassium’s Atomic Radius or its Ionic Radius
The K atom is larger because it has a whole extra shell vs. its ion which has lost the outer shell.
Practice: Explaining Trends
3
10/6/14
5. For the following pairs of atoms determine which is larger, draw a picture, and explain why:
a. Carbon or Oxygen
Carbon is larger; it has fewer protons than oxygen for the same number of
shells. The extra protons of oxygen are able to pull the same number of shells
closer in.
b. Magnesium or Calcium
Calcium is larger. It has one more outer layer of electrons than Magnesium.
a column, added shells win out over the extra protons to make the size relatively larger.
Going down
c. Lithium or Bromine
Not a very good question because there are two competing trends. Lithium ends up being larger because it
pulls very weakly on its few electrons, but bromine has many more shells so its too hard for me to ask this
one on a quiz.
6. For each pair of atoms determine which can steal an electron easier (higher electronegativity), draw a picture, and explain
why:
a. Oxygen and Fluorine
Fluorine steals better because its outer shell has been pulled in toward the protons into a closer area. It’s
easier for F’s protons to “get at” passing electrons.
b. Sodium and Potassium
Sodium is smaller, so its easier for it to steal an electron than K. Neither atom does this much, though,
because they generally lose electrons.
c. Boron and Calcium
Boron has more protons per/shell and it has fewer shells. Both of these features work together to make it
more likely to grab an electron vs. Ca.
7.
For each pair of atoms determine which can lose an electron easier (lower ionization energy), draw a picture, and explain
why:
a. Hydrogen and Helium
Hydrogen can lose its lone electron easier. It has one less proton than Helium, for the same number of shells
so it pulls a less effectively. Again, the atom with fewer protons/shell within a period holds its electrons with
less pull.
b. Boron and Aluminum
Aluminum can lose its electrons easier from the outer shell because it has MORE Shells. This factor causes
those valence electrons to be much farther out and easier to lose.
8. Which is bigger the ion or the atom (be sure to draw a picture and explain why).
a. Sodium atom or ion
The sodium ATOM is larger. It has one more shell than a sodium ion
b. Chlorine atom or ion
The chlorine ION is larger. It has one more electron in the same number of shells so those electrons are able
to roam out a little farther.
Practice: Explaining Trends
4
10/6/14