The document provides an overview of basic chemistry concepts including: - Matter is made up of elements which cannot be broken down further, with the main elements in the human body being oxygen, carbon, hydrogen, and nitrogen. - Atoms are the smallest unit of matter and contain protons, neutrons, and electrons. Electrons occupy different energy levels around the nucleus. - Ions are formed when atoms gain or lose electrons, acquiring a positive or negative charge. Chemical bonds such as ionic and covalent bonds are formed through the interaction of atoms. - Chemical reactions involve the formation or breaking of chemical bonds to rearrange matter without creating or destroying it.

1. Basic Chemistry

3. Basic Chemistry Matter – anything that occupies space and has mass Element – a substance that can’t be broken down to other substances The body is made mainly of O (oxygen), C (carbon), H (hydrogen), and N (nitrogen). It also consists of trace elements , which are needed, but only in small quantities (Ca, calcium; P, phosphorous; K, potassium; and S, sulfur).

5. Control Minus Nitrogen

6. Goiter – minus Iodine

7. The Atom The smallest unit of matter that still retains the properties of an element.

8. Structure of the Atom Has 3 basic particles: Proton – single unit of positive charge Electron –single unit of negative charge Neutron – no charge; neutral Nucleus – atom’s central core which contains the protons and neutrons Electrons orbit around the nucleus.

10. Periodic Table Using the periodic table, we can determine what the actual structure of an atom of a certain element. Atomic number – the number of protons in each atom of an element Mass number – the sum of the number of protons and neutrons in an atom’s nucleus Formula: Mass # - Atomic # = # Neutrons

13. Find the # of protons, neutrons, and electrons for each element.

14. Electron Arrangement Electrons determine how at atom will behave. Electrons occur in energy levels, sometimes called electron shells or orbitals. Depending on the atomic #, the atom can have 1, 2, 3, or more shells. Electrons in the outer shell have the most energy.

15. Electron Arrangement (con’t) Each shell can hold a certain # of electrons. Formula: 2(n 2 ) = # of electrons in the shell The # of electrons in the outer shell determines the chemical properties of the atom. Shells that aren’t completely full interact with other atoms.

17. Determine the # of protons, electrons, and neutrons for each. Then, draw the atom.

18. Ions An ion is an atom that has a positive or negative charge due to the loss or gain of electrons. Gain electrons = negative charge C -2 – carbon atom with 2 extra electrons Lose electrons = positive charge C +2 – carbon atom with 2 less electrons

19. Types of Ions Cations - have lost electrons (p+ > e-) giving them a positive charge. Anions - have gained electrons (p+ < e-) giving them a negative charge.

20. Isotopes Isotopes have the same number of protons and electrons, but a difference in the number of neutrons. Radioactive isotopes have decaying nuclei, which give off particles and energy. They are used in biological research and medicine as tracers.

25. Chemical Bonding Chemical Bond – an attraction between 2 atoms, resulting from a sharing of outer-shell electrons OR the presence of opposite charges on the atoms. Types of bonds: Ionic Covalent

26. Ionic Bonding Ions have a positive or negative charge. An ionic bond is the attraction between oppositely charged ions.

28. Covalent Bond Forms when 2 atoms share one or more pairs of outer-shell electrons. The number of covalent bonds at atom can form is equal to the number of electrons needed to fill its outer shell.

29. Chemical Reaction A process leading to chemical changes in matter; involves the making and/or breaking of chemical bonds. Chemical reactions cannot create or destroy matter, but only rearrange it. Reactant – starting material Product – ending material

30. 2H 2 + O 2  2H 2 O Product Reactants

31. Water Made of 2 hydrogen atoms and 1 oxygen atom joined by a covalent bond. It is a polar molecule, having opposite charges on opposite ends. This allows cohesion, which is the tendency of molecules to stick together via hydrogen bonds.

33. Solution A liquid consisting of a homogeneous mixture of two or more substances. Parts of a solution: Solvent – dissolving agent Solute – substance being dissolved Aqueous solution – water is the solvent

34. Acids and Bases Acid – chemical compound that donates H + to solutions Ex. HCl Base – chemical compound that donates OH - to solutions and accepts H + Ex. NaOH

35. pH Scale Scale used to describe the acidity or basicity of a solution Ranges from 0 – 14 0 – most acidic 7 – neutral 14 – most basic

37. Buffers Substances that resist changes in pH by accepting H + when there are too many, or donating H + when there is not enough.