Chapter 2 Chemistry of Life

ProtonsNeutronsElectrons Location (within an Atom) Charge (neutral, positive or negative) Relative Atomic Size (largest, smallest…?) Complete the Table in Your Notes

Unless told otherwise atoms are neutral.  What does this tell you about the number of protons, neutrons and electrons?  Protons = electrons  Number of neutrons can vary (they do not contribute to the charge) “Anatomy of an Atom”

 Atoms of same type have same number of protons! (it’s what makes an atom, an atom!)  All oxygen atoms have 8 protons  Can have different number of neutrons  Isotopes of the same element  Carbon-12 isotope versus Carbon-14 isotope --> Carbon-14 has TWO more neutrons Nucleus Consists of Protons and Neutrons held together by nuclear force.

 Found in energy levels around the nucleus  They are about 2,000 times smaller than protons or neutrons!  If an atom loses an electron, it will become positively charged.  If an atom gains an electron, it will become negatively charged.  We call these charged atoms ions. Electrons

 Tells number of protons (and electrons)  Use mass number to determine number of neutrons. Periodic Table

How many protons, neutrons and electrons?

 Why do atoms undergo bonding to form compounds?  To be stable and have a complete outer electron shell (energy level)  Ways to bond:  Share electrons  Give electrons  Take electrons Chemical Bonding

With your partner get: 19 pinto beans 19 popcorn kernels (each) and 24 red beans-DO NOT EAT THESE!!   Red beans = neutrons  Pinto Beans = protons  Popcorn kernels = electrons Use the Above to represent the nucleus of the following atoms:  Carbon-12  Carbon-13  Carbon-14 Arrange in energy levels: 2, 8, 8, 18… Use paper template…Do not Write on it!

When one or more electrons are transferred from one atom to another.  Like with Na and Cl  Forms charged atoms or IONS Ionic Bond

 Mg (atomic number = 12) bonds with Cl Show what would happen when….

 Electrons are shared between two atoms. Ex: Cl 2 Covalent Bond

Show covalent bonding in water (H 2 O)

 Inter= between (think interstate)  Attraction between molecules  Why we have liquid water and it isn’t all gas.  Forces hold neighboring water molecules together Intermolecular forces