The element sodium has an atomic number of 11and a mass number of 23 how many protons neutrons and electrons does one atom contain

Explanation:

Element sodium (Na) has an atomic number of 11

mass number = 23

proton = 11

electron = 11

Neutron = mass number - atomic number

= 23 - 11

= 12

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.