Calcium carbonate + (dilute) hydrochloric acid=?​

How are isotopes of the same chemical element alike? how are they different?

Astable electron arrangement for an atom is one that does not easily change. how is this arrangement arrived at? a. valence electrons are transferred or shared to create a full outer shell of electrons. b. valence electrons are discarded into space to create a full outer shell of electrons. c. protons (positive charge) pair with valence electrons (negative charge) to create a strong bond. d. outer shells with valence electrons are transferred or shared.

Chlorophyll a had the molecular formula c55h72mgn4o5 how many atoms are in this molecule