Why are diamonds so hard?
A) They are formed under very cold conditions.
B) They are held together by strong metallic bonds.
C) They are held together by strong ionic bonds.
D) They are held together by strong covalent bonds.
Answer: D
You might also like to view...
Less than half of the EU's energy needs are imported
Indicate whether the statement is true or false
Just above cumulus clouds, you would expect to find?
a. ?a stable layer. b. ?an unstable layer. c. ?a conditionally unstable layer. d. ?unusually strong horizontal winds. e. ?convective instability.
Saltating sand grains in a desert are carried by the wind and rarely more than 1 meter above the surface in normal circumstances
Indicate whether this statement is true or false.
If a stream-cut canyon is deep and narrow, which of the following is most likely to be true?
A. Rocks in the canyon walls are relatively hard and so easy to erode. B. The stream contains mostly small clasts, such as silt. C. The stream is probably close to its base level. D. Downcutting is occurring faster than widening.