What will be the ph when 50.0 ml of 2.00m carbonic acid is mixed with 20.0 ml of 3.00 m sodium bicarbonate? the ka of carbonic is 4.30 x 10-7
for the above buffer system, what will be the ph when (a) 15.0 ml of 0.500 m hcl and (b) when 15.0 ml of 0.750 m nach is added?

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)