1. Identify the following as metals, nonmetals, or metalloids using the periodic table.
(a) silicon (Metalloid)
(b) fluorine (Nonmetal)
(c) uranium (Metal)
(d) mercury (Metal)
(e) arsenic (Metalloid)
(f) iridium (Metal)
2. List three differences in the physical properties between metals and nonmetals.
Metals are shiny, malleable and good conductors whereas nonmetals are dull,
brittle an insulators.
3. An element has an electron configuration of [Kr]5s24d7. Determine whether this element
is a metal or a nonmetal without looking at a periodic table. How can this be determined?
It is a metal because it it only has two valence (outer level) electrons. Metals
tend to have 3 or less valence electrons.
4. How do metals and nonmetals differ in terms of how they lose/gain electrons.
Metals tend to lose electrons and nonmetals tend to gain electrons.
5. Why are most of the elements on the left and in the middle of the periodic table metals?
Because most of them have 3 or less valence electrons.
6. Halogens tend to gain electrons when they react making them nonmetals. How many
electrons do the halogens tend to gain? Why?
Halogens tend to gain one electron so that they can get a full outer level and be
stable.
7. What is a semiconductor?
A substance that conducts electricity, but poorly.
8. Why are metalloids used to make semiconductors?
Metalloids have properties between metals (conductors) and nonmetals
(insulators) and so they can conduct electricity but not very well.
9. An element has the electron configuration [Ar]4s23d104p4. Using the electron
configuration and a periodic table answer the following questions.
(a) What is the element? Selenium
(b) What group is it in? 16
(c) What period is it in? 4
(d) Is it a metal, nonmetal, or metalloid? nonmetal
(e) List three properties of this substance? Dull, brittle, insulator.
(f) What element(s) might it behave like? Sulfur or Tellurium.
(g) How many valence electrons does it have? 6
(h) When it reacts will it tend to gain or lose electrons? gain
(i) How many electrons will it tend to gain or lose? gain 2 electrons