4. W 350 g wody rozpuszczono 100g cukru. Jakie jest stężenie % tego roztworu ? 5. W 400g roztworu znajduje się 80g soli. Jakie jest stężenie % tego roztworu ? 6. Zmieszano 450g wody i 50g kwasu. Oblicz stężenie % powstałego roztworu. 7. Do 250 g wody dodano 50g soli. Jakie stężenie % ma ten roztwór ? 8. W 500g roztworu znajduje się 25 g kwasu. Oblicz stężenie % .

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products

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 is conclusions.i think so