Hey,
A mole is a unit of measure that helps us compare particles of any given substance and its mass. ... The molar mass, also known as molecular weight, is the sum of the total mass in grams of all the atoms that make up a mole of a particular molecule. The unit used to measure is grams per mole.
Closed system. If the system is not closed, matter or energy can escape from the system. an example of this is if you react magnesium and hydrochloric acid in a open system. The H₂ gas is going to escape making it look like some of the mass disappeared . in that same reaction some in an open system will also loose heat to the surrounding which will make it look like less heat was produced.
Pressure does not affect the voltage produced in a voltaic cell.
I think it is the letter A because they both Make sense
Adenine , guanine, cytosine and thymine