Chemical Level of Organization

Matter and Mass Matter: anything that takes up space and has mass Mass: the amount of material in matter

Atoms Atoms are the smallest stable units of matter Air, elephants, rocks, oranges, oceans, and people are all made up of atoms in different combinations Unique characteristics are a result of the types of atoms and the way they combine and interact Atoms are composed of subatomic particles

Subatomic Particles Protons Neutrons Electrons Protons and neutrons are similar in sixe and mass but a proton (p + ) has a positive charge and neutrons (n or n 0 ) are electrically neutral, or uncharged. Electrons (e-) are much lighter than protons (1/1836) and have a negative electrical charge

Atomic Structure Atoms usually contain equal numbers of protons and electrons Atomic Number: the number of protons in an atom Hydrogen: atomic number:1 How many protons and electrons does it have? 1 of each

Atomic Structure Protons and Neutrons are located in the center of the atom and form the nucleus Electrons travel around the nucleus at high speeds forming a spherical: electron cloud To demonstrate this it is often illustrated in a 2-dimensional electron shell Electrons remain in the shell due to electrical force, the negatively charged electron is attracted to the positively charged proton The largest of atoms is 0.05nm or in

Element A pure substance composed of atoms of only 1 kind 92 exist in nature Cannot be changed or broken down into simpler substances 13 most abundant in the human body include: Oxygen, carbon, hydrogen, nitrogen, calcium, phosphorus, potassium, sodium, chlorine, magnesium, sulfur, iron, and iodine Body also contains numerous trace elements

Isotopes Atoms of the same element whose nuclei contain the same number of protons, but different numbers of neutrons Mass number: the total number of protons plus neutrons Hydrogen has 3 isotopes Hydrogen-1 or 1 H: 1 proton Hydrogen-2 or 2 H: 1 proton and 1 neutron Hydrogen-3 or 3 H: I proton and 2 neutrons

Atomic Weight The actual mass of an atom Measured in daltons Also known as amu, or atomic mass unit

Elements in the Human body Poster Project