Question

1. sodium and chlorine reacting and changing into salt is an example of which type of change in matter? a. chemical change b. physical change c. reactionary change d. explosive change 20. liquid gold poured into a mold and hardening into a ring is an example of which type of change in matter? a. chemical change b. physical change c. solidification change d. molded change

Explanation:

A physical change is a change in the form or state of matter without changing its chemical composition. Liquid gold being poured into a mold and hardening into a ring only changes its state from liquid to solid without altering its chemical makeup. A chemical change involves a change in chemical composition, like sodium and chlorine reacting to form salt. Solidification is a type of physical change where a liquid turns into a solid.

Answer:

1. B. physical change
2. A. chemical change