I believe the answer is two
Ca.
Hydrogen and Carbon combined
Zn = zinc which is a metal, not a carbon atom
Cl=chlorine, just not a carbon atom
Sn isn’t a carbon atom.
I Am positive that it is Ca because Ca means carbon

The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum. Each element's emission spectrum is unique. Therefore, spectroscopy can be used to identify elements in matter of unknown composition. Similarly, the emission spectra of molecules can be used in chemical analysis of substances.
Answer:
Earth is the only planet in the solar system with large quantities of surface water, and with water comes all the things that dissolve in it, including salt.
Explanation: