What is the difference between an atone and a molecule

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

How many moles of sulfur dioxide are produced when 4.38 moles of oxygen completely react with iron (iv) sulfide