Which elements are likely to be the Most reactive metals, based on the number of valence electrons? Why?*
O Group 1/1A becuase it has one valence electron
O
Group 3/3A because it has both metals and metalloids
о
Group 17/7A because it has 7 Valence Electrons
Group 18/8A because it has 8 Valence Electrons

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.

i think so it’s will be b yes i believe its

he would use the colour black

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.