So like always, pause this video and try to figure this out on your own and this periodic table ofĮlements will prove useful. We are asked to calculate the number of moles in a 1.52 So the final answer should be reported as 180.16 g/mol.
So the 5 digit get upgraded to a 6 in the answer. Since the number we're discarding (6) is larger than 4 we round the digit it is next to up one number. So we only want the 1 and 5 digits and want to discard the 6. But because we only have two decimals digits for the 72.06 and 96.00 numbers, our answer is limited to two decimal digits. So after multiplying Sal is performing this calculation: 72.06 + 84.156 + 96.00, which mathematically would yield 180.156. For addition the sig fig rule is that we can only have as many decimal digits as do in the calculation number with the lowest number of decimal digits. You should look into sig figs in greater detail, but in this problem Sal is adding three numbers together. And the rules we use to judge how many digits are permissible are significant figures, or sig figs. But in science we are more conservative with the digits we use because of the precision of our measuring instruments. After a calculation would be able to use all the digits of the final number as our answer if we only wanted a mathematical answer. However, even these small quantities are required for the body to function properly.It's important to keep in mind significant figures are important for doing calculations in a science like chemistry. These last three metals are present in the body in very small quantities. Cobalt is a necessary component of vitamin B-12, a vital nutrient. Manganese is needed for the body to metabolize oxygen properly. Copper is also needed for several proteins to function properly in the body. Zinc is needed for the body’s immune system to function properly, as well as for protein synthesis and tissue and cell growth. Other transition metals have important functions in the body, despite being present in low amounts. It is the presence of this particular transition metal in your red blood cells that allows you to use the oxygen you inhale. Each hemoglobin molecule has four iron atoms, which act as binding sites for oxygen. The crucial atom in the hemoglobin protein is iron. Hemoglobin is a relatively large molecule, with a mass of about 65,000 u. Hemoglobin combines with oxygen and carbon dioxide, transporting these gases from one location to another in the body. The critical part of the red blood cell is a protein called hemoglobin. Without red blood cells, animal respiration as we know it would not exist. Red blood cells are cells that transport oxygen from the lungs to cells of the body and then transport carbon dioxide from the cells to the lungs. Iron is a transition metal and the chemistry of iron makes it a key component in the proper functioning of red blood cells. Because iron has relatively massive atoms, it would appear even lower on a list organized in terms of percent by atoms rather than percent by mass. The most abundant non-main group element is iron, at 0.006 percentage by mass. Most of the elemental composition of the human body consists of main group elements. To Your Health: Transition Metals in the Body Each group is located in a different part of the periodic table. Elements are either metals, nonmetals, or semimetals.