Which one of the following is a correct set?
Diamond, sp2
Graphite, sp3
Diamond, sp
Graphite, sp2
How many corners of SiO4 units are shared in the formation of three dimensional silicates?
3
2
4
1
Which one of the following elements on doping with germanium, make it a p-type semiconductor?
Boron
Selenium
Arsenic
Germanium
Pure silicon doped with phosphorus is
amorphous
p-type semiconductor
n-type semiconductor
insulator
C.
n-type semiconductor
Doping means incorporating small amount of foreign impurity. Doping of group 14 elements such as silicon with group 15 elements such as phosphorous give rise to excess electrons are called n-type semiconductor (as negative charge flows).
Which one of the following correctly represents the variation of electronegatrvity (EN) with atomic number (Z) of group 13 elements?
Al3+, Fe3+, Zn2+ and Ni2+ ions are present in an acidic solution. Excess of ammonium chloride solution followed by addition of ammonium hydroxide solution. The available precipitate will contain
Zn(OH)2 and Ni(OH)2
Al(OH)2 and Fe(OH)3
Zn(OH)2 and Al(OH)3
Ni(OH)2 and Fe(OH)3