During a lab investigation a scientist heats a solid substance. The scientist observes that the solid
has two different melting points. The scientist
is able to separate the two resulting liquids.
Which statement best classifies the original solid
substance?
A.
It was an atom.
B.
It was a mixture.
0.
It was an element.
D. It was a compound.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

< > according to newton's third law of motion, forces always act in equal but opposite pairs. another way of saying this is for every action, there is an equal but opposite reaction.< >