Answer:
D. 76%
Explanation:
Percent yield=actual/theoretical * 100
38/50 * 100 = 76%
Answer: During a phase change, such as melting or boiling, the kinetic energy increases.
Explanation:
Kinetic energy is the energy obtained by the molecules of a substance due to their motion.
When phase change such as melting or boiling takes place then it means heat is absorbed by the substance. As a result, their molecules more even more rapidly from one place to another due to which more number of collisions take place.
Hence, a change in phase of substance occurs as kinetic energy increases in melting or boiling process.
Thus, we can conclude that during a phase change, such as melting or boiling, the kinetic energy increases.
Discovered and isolated radium and polonium in 1898
A closed system is completely closed to the outside environment. Every interaction is transmitted inside that closed system.