What is the total number of neutrons in the nucleus of a neutral atom that has 19 electrons and a mass number of 39

Suppose a lab group reports a ppercent yield of sand of 105. is it really possible to collect more sand than was originally represented? what is the possible explanation for the extra product?

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process

Which of the following is a conclusion that resulted from ernest rutherford’s scattering experiment? (will mark brainliest) a. the nucleus is negatively charged b. the atom is a dense solid and is indivisible c. the mass is conserved when atoms react chemically d. the nucleus is very small and the atom is mostly empty space