Given a scientific question, generate a correct answer to it.

[EX Q]: A change in one or more physical properties of matter without any change in chemical properties is called what?
[EX A]: physical change

[EX Q]: The properties of the alkali metals are similar to each other as expected for elements in the same what?
[EX A]: family

[EX Q]: What is required for communication?
[EX A]:
transmission and reception of signals