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Chemistry. Matter. All living things are made of matter Cannot be created or destroyed. Atoms. Smallest unit of an element that still has the same chemical properties Three subatomic particles Protons + (inside nucleus) Neutrons 0 (inside nucleus) Electrons – (outside nucleus).
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Matter • All living things are made of matter • Cannot be created or destroyed
Atoms • Smallest unit of an element that still has the same chemical properties • Three subatomic particles • Protons + (inside nucleus) • Neutrons 0 (inside nucleus) • Electrons – (outside nucleus)
Periodic Table • Letter is the atomic symbol • Atomic number is how many protons the atom has • Atomic mass is the number of protons and neutrons • In a neutral atom protons And electrons will be the same
Element • substances that can’t be broken down chemically into simpler substances • Examples- • Hydrogen • Oxygen
Molecule • 2 or more atoms come together to make a molecule • Examples • H2 • H2O • C4
Compound • 2 or more elements together in a fixed ratio. • Examples: • H2O, NH3, NaCO3 • For every 1 oxygen, there are 2 hydrogens • All compounds are molecules, but not all molecules are compounds
Electron shells • Areas of electrons around the nucleus • Atoms have 2 electrons in the first shell • 8 in the following shell • Sulfur can bond with 2 other molecules
Valence Electrons • The amount of electrons in the outer shell • Determine chemical properties • Determine how many bonds they can make
Valence Electrons • When outer most energy shell is not full, atoms find ways to fill energy shells by taking, giving away or sharing electrons
Lewis Dot Diagrams • An easy method to show outer energy shell and predict how the elements will bond together. • Shows valence electrons only
Types of bonds • Ionic Bonds- One or more electrons get passed to another element • Very weak bond • Na will pass one e- • Chlorine will accept one e-
Types of bonds • Covalent bonds- Share electrons between two elements • Very strong bond • Polar covalent- shares electrons unequally (will be a charge) • Non-polar covalent- shares electrons equally
Types of bonds • Hydrogen bonds- attractive interaction of a hydrogen atom with an electronegative atom • Weak by itself • Strong when there are many Water depends on H-bonds
Chemical reactions (rxn) • Making or breaking of chemical bonds • Reactants- left side of the equation, what goes into reaction • Products- right side of the equation, what comes out of the reaction • Comment: All atoms in the reactants must be accounted for in the products
Chemical rxn examples • 2H2O 2H2 + O2 • H + Cl HCl • Number at front means 2 water molecules • Subscript numbers represent the amount of H in the molecule
Biochemistry • Study of compounds found in living things • Organic compounds- always contain Carbon • Important Elements in Biology: HONC P S • HONC for Biology!!
Metabolism • All chemical activities and changes that happen in a cell or organism • synthesis: building up • decomposition: breaking down
Types of reactions • Synthesis rxn- Simple molecule + simple molecule Complex molecule Decomposition rxn- Complex molecule simple molecule + simple molecule
Bonds • Making complex molecules takes energy! • Breaking down a complex molecule releases energy!
Homework/Classwork • Draw one square from the periodic table on a half sheet of computer paper. Include: • Atomic number • Atomic mass • Name of element • Lewis Dot diagram • 5 pictures of molecules that include your element • 3 reasons why your element is important in Biology (being part of living things is not enough)