Suppose the half-life of an isotope is 10 years. after how many years will half of this isotope have decayed into its daughter elements?

5 years
10 years
20 years

Write the complete balanced equation for the reaction between lead (iv) oxide (pbo2) and water (h2o).

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.

The mass of a neutron is equal to the mass of a proton plus the mass of an electron. true or false false true