Which of the following describes what occurs as a solid becomes a liquid?
a) chemical change occurs; the particles of the solid vibrate more slowly and their kinetic energy decreases.
b) chemical change occurs; the particles of the solid vibrate faster and their kinetic energy increases.
c) physical change occurs; the particles of the solid vibrate more slowly and their kinetic energy decreases.
d) physical change occurs; the particles of the solid vibrate faster and their kinetic energy increases.

Classify each statement about effective nuclear charge, zeff, as true or false.

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.

Avariable that is not being directly tested during an experiment should be