How do we classify substances into asids and bases?please tell me I have an exam

To determine whether a substance is an acid or a base, count the hydrogens on each substance before and after the reaction. If the number of hydrogens has decreased that substance is the acid (donates hydrogen ions). If the number of hydrogens has increased that substance is the base accepts hydrogen ions

Explanation:

Hope it helps

there on the beach was a struggling turtle.   around its bright green neck was a loop of soda can rings.   in order to the planet, i have made a few changes to my life.   the first change is reducing the number of straws used. the second change was to recycle.   finally, i have worked hard to clean up litter.   it is important to clean our ocean.

you may not think straws have a large impact but they do.   imagine for every straw you sip out of a poor, , adorable turtle is being harmed.   one way i chipped in to is by using metal straws.   these straws are reusable and inexpensive.   another change is simply turning down straws.   by refusing a straw, i’m the turtles one drink at a time.  

however, the ocean just doesn't have turtles.   there are lots of creatures that live there and are harmed by all the litter.   to prevent litter from growing it’s important to recycle.   for me, i have started to buy most goods that are made out of recycled material.   pura vidas, chacos, purses, and too many other items to even count.   plus, when you buy those products they give money to charities.   not only am i the environment, but i’m also feeling better about my self.   finally, i have worked hard to clean up litter.   it is important to clean our ocean.

explanation:

the answer is

r ≈5.641

plug in the area of 100 yards into the equation

100=

divide each side by pi

≈ 31.8309=

take the square root of each side to find r

=r

r ≈5.641