Working with my friend right now, we got stuck if anyone can help.

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~

What is the percent by mass of magnesium sulfate in mgso4.7h2o

Which of the following best describes technology a. something created for only scientists to use b.the method of thinking that scientists use. c.the application of engineering to create useful products. c. a scientific idea