3. explain why multicellularity of an organism requires cell-to-cell communication.

In multicellular organisms (such as yourself), cell-cell signaling allows cells to coordinate their activities, ensuring that tissues, organs, and organ systems function correctly.  I hope this helps.

the answer is admiramos

the rule for verbs is whoever you are referring to (in this case 'nosotros'), you need to change the ending of the word.

nosotros - amos

yo - o

tu - as

el, ella, usted - a

ellos, ellas, ustedes - an

(examples: nosotros bailamos (instead of bailar) or yo hablo (instead of habla)

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.