Matter can be separated or changed, but in a closed system, the number and types of atoms remains constant.
No resources have been tagged as aligned with this standard.
Under these standards, classifying specific changes as chemical or physical is not appropriate.
Physically combining two or more substances forms a mixture, which can be separated through physical processes.
When substances interact and form new substances the properties of the new substances may be very different from those of the original substances, but the amount of mass does not change.