You have an atom with 3 protons ,4 neutrons ,and 3 electrons .adding a neutron will

Explanation:

Adding a neutron will not affect the charge. The atom remains neutrally charged.

Since the charge of a neutron is neutral, or 0, the charge is not affected. Protons have a positive charge, whereas electrons have a negative charge. Since there are an equal number of protons and electrons, they cancel out.

Adding a neutron also increases the mass by 1. The mass of a neutron is 1 amu. The atomic mass is calculated by protons + neutrons.

Originally, the mass is 7 (because 3+4). The mass would now be 8 (because 3+5).

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.

there are no statements provided but here is why:

sulfur belongs to group 16 because it can be found in nature whether it is in a free or combined state.

hope this