The law of conservation of matter states that matter cannot be created or destroyed. this law applies when a chemical change occurs. the number of atoms present before a chemical change is the same as the number of atoms present after the change. the atoms may be combined in a new way, but the overall number of atoms remains unchanged. using the law of conservation of matter, if i started an experiment with 200 atoms of matter, how many atoms would i have after the chemical change? question 1 options: 100 200 300 400

Write the chemical symbols for three different atoms or atomic cations with 27 electrons. asap!

Maria wants to determine which type of disinfectant kills the most bacteria. which of the following is the best way for maria to determine this? a. ask ten different companies that make disinfectants which type is best. b. put the same amount and species of bacteria on ten identical plates, and add ten different kinds of disinfectant to each plate. c. interview ten different people to determine which type of disinfectant they prefer. d. put the same amount and species of bacteria on ten identical plates, and add a different disinfectant to each plate.

What forms when chemical reactions combine pollution with sunlight?