I do not agree with the statement.
The "substance" can be a compound. It's "pure"
as long as there's nothing else in it but its name.
'Pure' water is 100% H₂O with nothing else in it.
'Pure' table salt is 100% NaCl with nothing else in it.
'Pure' carbon dioxide is 100% CO₂ with nothing else in it.
These example substances are all compounds, not elements.
Answer:
The answer is "
".
Explanation:
Cavity and benzene should be extended in equal quantities.



B. is not a validated bu experimentation
Answer:
2.7 s
Explanation:
The period of the motion of a massless loaded spring is given by

where m is the mass of the load and k is the force or spring constant.
Using values in the question and converting to appropriate units,
