SeatonChapter 2 The Chemical Level of Organization2.1 Elements and Atoms: The Building Blocks of MatterMatter-Anything that occupies space and has massMass – amount of matter contained in the objectWeight- is the objects mass affected by the pull of gravityThree state of matter: solid, liquid, and gasCan you think of three states of matter that are solid, liquid and gas in the human body?Did you know that an object of a certain mass weighs less on the moon, for example,than it does on Earth because the gravity of the moon is less than that of Earth? In other words,weight is variable, and is influenced by gravity. A piece of cheese that weighs a pound on Earthweighs only a few ounces on the moon.All matter in the natural world is organized into one or more elements. An element________________________________________________________________________________________________________________.Major Elements of Human Body (Figure 2.2)Oxygen (O) : ____%Carbon (C) : ____%Hydrogen (H) : ____%Nitrogen (N) : ____%1
SeatonDid you know almost 99% of the mass of the human body is made up of six elementsoxygen, carbon, hydrogen, nitrogen, calcium and phosphorus. Can your body make elements? Ifnot, were do they come from?Anatomis the smallest quantity of an element that retains the unique properties of that element.Different elements contain different numbers of subatomic particles which helps to determine theunique properties of each element.Most atoms don’t exist in a free state but instead chemicallycombine with other atoms to form molecule and compounds. Although these two words can beused interchangeable there is a distinct chemical difference between the two.Molecule•Two or more atoms bonded together (e.g., H2or C6H12O6)oatoms share electronsCompoundsA substance composed of two or more elements joined by chemical bonds.Example: H2Oomost important & abundant inorganic compoundoprimary component of bodyAtoms are made up of even smaller subatomic particles, three types of which are important: theproton, neutron, and electron (Figure 2.3).Determine the charge and location of the following subatomic particles1.electrons2.protons3.neutronsElectron clouds (shells)is a layer of electrons that encircles the nucleus.Electrons can occupyup to seven electron shells. The first electron shell can hold two electrons and the second electronshell can hold a maximum of eight electrons.Electrons in thevalence shell(outermost electronshell) have the most potential energy and are the most chemically reactive electrons.