Worksheet:
Density, Atomic and Ionic Radii – Key
1. Which of the alkali metals has the greatest density?
Francium
2. Which transition element has the greatest density (See Table A-3 page 856)?
Iridium
3. Atoms of which alkaline earth metal are the smallest?
Beryllium
4. Atoms of which halogen are the largest?
At
5. Rank the following ions from smallest to largest: Mg2+, Al3+, P3-, O2-.
Al3+ < Mg2+ < O2- < P36. What is the most reactive metal in the periodic table?
Francium
7. What is the most reactive nonmetal in the periodic table?
Fluorine
8. What is the shielding effect?
Energy levels between the nucleus and the outer level electrons block (shield)
the nucleus from being able to attract the outer level electrons
9. What is effective nuclear charge?
It represents the amount of attraction the nucleus has for its electrons
10. What is larger N or N3-? Explain.
N3In N there are 7 electrons but in N there are 10 electrons. The 7 protons in the nucleus of a
nitrogen atom cannot hold on to 10 electrons as effectively as it can hold on to 7 electrons.
3-
11. Why is a Nitrogen atom larger than an Oxygen atom?
Oxygen and nitrogen each have two energy levels of electrons to hold on to however oxygen
has 8 protons to hold on to the two levels whereas nitrogen has only 7 protons. Therefore
Nitrogen’s nucleus is less effective at holding on to its electrons.
12. Why is a Chlorine atom larger than a Fluorine atom?
Chlorine has 3 energy levels and fluorine has only 2 energy levels.
Fluorine is more effective at holding on to its 2 energy levels than chlorine is at holding on
to three and therefore pulls them in closer
making fluorine a smaller atom.