I think the major difference is that 0.5 is exactly equal to a half. The other 0.555555 is equal to a half plus five hundredths plus thousandths plus five ten thousandths plus five hundred thousandths, plus five millionths and so forth; and therefore it is greater than 0.5. In other words 0.555555 is called a recurring decimal.
Hormones travel through the body by using blood streams, such as veins. The hormones then get to the target cell by moving through the liquids surrounding the cells. They then change how the cell works, thus changing the body.
Mass is protons + neutron so the mass number is 14