An atom is the smallest you can get to identify the element.
The correct answer is C) A substance changes color when heated, but changes back when cooled. Hope this helps.
Answer:
you dony have a picture for me to match them
Explanation:
the oxidation states of the elements before and after the reaction is;
Pb oxidation state changes from 0 to +2
SO₄²⁻ ion there's no change in the oxidation state during the reaction
Au oxidation state changes from +3 to 0
reduction reactions are when there's a decrease in the oxidation state of the species
oxidation reactions are when theres an increase in the oxidation state of the species
the element where there's a decrease in oxidation state is Au.
Therefore Au gets reduced.
answer is B) Au
