•describe the various types of testing done to ensure the effectiveness of ads and discuss the rationale for each of these tests. understand the various types of pretests and posttest including lab tests, field studies, starch tests, day after recall, concept tests, etc. • what is the difference between a lab test and field test?

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

i don't see a text, but i am gonna assume this *orbit* the curved path, usually elliptical, described by a planet, satellite, spaceship, etc., around a celestial body, as the sun.

air

in a tire you fill a tire with air

then a couple days later you check the air pressure in the tire

hope this mark me brainliest