if you add or remove one component will it change the chemical identity of the materials or the other components

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

What occurs when a cell engulfs large food particals

Plz a person walks 1 mile every day for exercise, leaving her front porch at 9 am and returning to her front porch at 9: 25 am what was the total displacement of her daily walk a. 1 mile b. 0 c. 25 min d. none of the above