BASIC CHEMISTRY Unit 2: Biochemistry

What are buildings made of?

What are living things made of?

Everything in universe is composed of MATTER Matter = anything that has mass and occupies space SOLID LIQUID GAS

** All matter composed of elements ** Element = substance that cannot be broken down chemically into simpler substance 6 elements essential to living organisms: Carbon (C) Hydrogen (H) Nitrogen (N) Oxygen (O) Phosphorus (P) Sulfur (S) CHNOPS

Atom = smallest unit of matter “atmos” – unable to cut Subatomic particle ChargeLocation Mass (Atomic Mass Unit – AMU) Protons Neutrons Electrons Atoms consist of subatomic particles

Subatomi c particle ChargeLocation Mass (Atomic Mass Unit – AMU) Protons+Nucleus1 Neutrons No charge (neutral) Nucleus1 Electrons Protons & Neutrons -Protons & neutrons have the same mass = 1 AMU (Atomic Mass Unit) -1 AMU = x grams -Strong forces bind protons & neutrons together to form the nucleus, which is at the center -Protons have a positive charge (+) -Neutrons carry no charge (neutral) PROTONNEUTRON NUCLEUS “center”

Subatomi c particle ChargeLocation Mass (Atomic Mass Unit – AMU) Protons+Nucleus1 Neutrons No charge (neutral) Nucleus1 Electrons-Shell0 Electrons -Electrons very very very small and have mass of 1/1840 of proton mass = 0 AMU -Located in shells surrounding nucleus -Negatively charged (-) ELECTRON SHELL

**Atomic Number (# of protons) determines what element is ** Atomic number = # of protons Element Name (represented by 1 or 2 letter symbol) Mass number = # of protons + # of neutrons

2 nd SHELL Shells NUCLEUS1 st SHELL 3 rd SHELL ** Electrons arranged in SHELLS around the nucleus ** 1 st shell = 2 electrons 2 nd shell = 8 electrons 3 rd shell = 8 electrons 15 protons 15 neutrons 15 electrons

Draw an example of an Oxygen (O) atom

8 protons 8 neutrons 8 electrons Atomic number = 8 Mass number = 16

Draw an example of an sulfur (S) atom 16 protons 16 neutrons 16 electrons Atomic number = 16 Mass number = protons 16 neutrons

Isotopes = atoms of same element with different # of neutrons ** isotopes have different mass number (# protons + # neutrons) -Nuclei are unstable and break down at a constant rate over time -Geologists can determine the ages of rocks and fossils by analyzing the isotopes found in them

Compound = 2 or more elements bound together Molecule = smallest part of compound that has properties of the compound Na (sodium) Cl (chlorine ) NaCl (salt) H (hydrogen) O (oxygen) H 2 O (water)

Chemical formula = indicates # of each kind of atom in a molecule H2OH2O H = 2 atoms O = 1 atom C 6 H 12 O 6 C= 6 atoms H = 12 atoms O = 6 atoms CH 4 C= 1 atom H = 4 atoms O3O3 O = 3 atoms

Chemical Bonds chemical bonds Atoms in compounds are held together by chemical bonds. Bond formation involves ELECTRONS 3 main types of Chemical bonds – Ionic = formed when one or more electrons are transferred from one atom to another – Covalent bond = formed when electrons are shared between atoms – Hydrogen bond = attraction of slightly positive (+) hydrogen atom to slightly negative (-) atom  weak bond

Ionic Bond = formed when electrons are transferred from one atom to another Such charged particles called IONS Protons + 11 Electrons – 11 Charge = 0 Protons + 17 Electrons – 17 Charge = 0 Protons + 11 Electrons – 10 Charge = +1 Positive charged Protons + 17 Electrons – 18 Charge = -1 Negative charged

Covalent Bond = formed when 2 atoms share electrons

Hydrogen bond = weak attraction of slightly positive hydrogen atom (+) to slightly negative atom (-) in vicinity

What type of bond and why?

Summary of Ionic and Covalent Bonds