Tính pH của dung dịch sau khi trộn 100 ml dung dịch NaOH 0,1M với 100 ml dung dịch HNO2 0,2M. Biết pKHNO2 = 4,1.

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.

Which of the following are correct values for the ideal gas laws constant r