What is the difference in concentration of hydronium ions in a solution of pH 2.0 compared with one of pH 7.0?

Always use significant figure rules. remember that these rules apply to all numbers that are measurements. if a vector that is 3 cm long represents 30 km/h, what velocity does a 5 cm long vector which is drawn using the same scale represent? a.100 km/h b.60km/h c.50km/h

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point

Pentane with molecular formula c5h12, exists in three isomeric forms. one shows linear carbon chains, another has one -ch3 groups present on the third carbon atom, and the third has two -ch3 groups present on the second carbon atom. what types of isomers are these? a. geometric isomers b. structural isomers c. halotropic isomers