Answer:
False
Explanation:
It is wrong to claim that when the attraction between particles overcomes their motion, the particles will clump together to boil.
During boiling particles do no clump together, they tend to move apart more rapidly.
- Boiling occurs when the vapor pressure overcomes the ambient atmospheric pressure.
- The hotter part of the boiler close the heat source moves rapidly away because they have become less dense.
- The colder and denser part sinks and this interaction sets up a convection cell.
The answer is b) light waves travel faster than sound waves.
Answer:
Ionic bonds hold charged particles in solid NaCl together, such that they are unable to move or conduct electricity.
Explanation:
Consider an electric current that flows through a conductor: charge moves in a uniform direction from one end of the conductor towards the other.
Thus, there are two conditions for a substance to conduct electricity:
- The substance shall contain charged particles, and
- These charged particles shall be free to move across the substance.
A conductor of electricity shall meet both requirements.
Now, consider the structure of solid NaCl
. NaCl is an ionic compound. It contains an ocean of oppositely charged ions:
- Positive
ions, and - Negative
ions.
Ions carry charge. Thus, solid NaCl contains charged particles and satisfies the first condition.
Inside solid NaCl
, electrostatic attractions ("ionic bonds") between the oppositely charged ions hold these ions in rigid ionic lattices. These ions are unable to move relative to each other. As a result, they cannot flow through the solid to conduct electricity. Under solid state, NaCl is unable to satisfy the second condition.
As a side note, melting NaCl into a liquid breaks the ionic bonds and free the ions from the lattice. Liquid NaCl is a conductor of electricity.