Somebody please help me!!

The given isotope is Br 80

If 35 protons present then its atomic number is 35

Mass number is 80 so its meutrons are 45 because proton+ neutron = mass number

Its electron are 36 because of negative one charge

Explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

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