Why is doing research if you're creating the procedure for an experiment?
a. someone else may have results you can copy for yourself.
b. it can you avoid problems with your experiment not working.
c. research lets you know if your hypothesis is correct ahead of time.
d. online sources will tell you what your independent variable should be.

answer:

a is right but also wrong dont copy off of someone elses

b is right

c and d you need that for yourself

explanation:

- lead + phosphoric acid = hydrogen + lead(ii) phosphate

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.