two electronics technicians are discussing conductors and insulators. technician a says that conductors have more free electrons than insulators. technician b says that insulators have lower resistance than conductors. which of the following statements is correct?
a) only technician a is correct
b) only technician b is correct
c) both technician a and technician b are correct
d) neither of the two technicians is correct
2007-03-24 04:56:57 · 5 answers · asked by Lynn D 1 in Science & Mathematics ➔ Engineering
(a)
2007-03-24 05:22:20 · answer #1 · answered by purimani2005 4 · 0⤊ 0⤋
Technician A is partially correct but the answer is vague. Electron valence is the number of electrons in an incomplete outermost shell (valence shell). The maximum number of electrons the valence shell can hold is 8. If the valence shell is complete (8 electrons) it has a valence of 0. Copper for instance has 29 electrons, hence its position on the periodic table of the elements is 29 (atomic weight). Copper has 1 electron in its valence shell so its electron valence is 1. Copper is a good conductor. Carbon has 4 electrons in its valence shell so its electron valence is 4. Carbon is what we call a semiconductor. All semiconductors such as carbon, silicon, germainium have an electron valence of 4. So as you can see the more electrons that are in the valence shell the conducting property of an element will decrease because if an atom holds 8 electrons in the outer shell it is a stable element. A true insulator will have a valence shell with 8 electrons. When we talk about electricity, what we call current is actually the electrons in the valence shell of an element (copper) moving from one atom to another. So we can say that an atom with an electron valence of 1,2 or 3 is a conductor with 1 being the best. An electron valence of 4 is a semiconductor and an electron valence of 5,6,7 or 8 is an insulator with 8 being the best. So while copper has fewer electrons in its outer shell than an insulator, the electron(s) it does have can move from one atom more freely. When talking about the conductance properties on an element we are only concerned with the electrons in the outermost shell.
2007-03-24 05:53:35 · answer #2 · answered by baditude43138 1 · 1⤊ 0⤋
technician a is correct.
metals have more free valence electrons and therefore are conductors. insulators have high resistance, thats why they don't conduct.
2007-03-24 07:31:58 · answer #3 · answered by mastertofu77 2 · 0⤊ 0⤋
a) is the right answer because Insulators have to have higher resistance so electricity can't pass through. If they had lower they would turn into conducters.
2007-03-24 05:08:20 · answer #4 · answered by Person 2 · 0⤊ 0⤋
the correct answer is a)
2007-03-24 05:06:50 · answer #5 · answered by Lucas01 2 · 0⤊ 0⤋