How are elements classified organized?

Achemist has dissolved a certain substance in water. the chemist knows that more of the substance could be dissolved into the water before it stops dissolving. therefore

Covalent compounds: mastery test select the correct answer what is formed when atoms join together with a covalent bond? a. an ion b. a molecule c. a neutral atom d. a noble gas

Ok, so i have 2 questions. try to answer them both: (the topic is fire) 1) how can you represent the chemical reaction of fire? 2) what kind of bond is formed in this chemical reaction