CHEM 21.31 Topic 1.3 - Atomic Structure

Polymers

material of choice for a host of everyday objects

Polymers

made up of very large molecules made up of many smaller molecules linked together

Polymer backbone

long chain of bonded atoms formed when monomers link together

Polyethylene

produced if there is 1 carbon atom and 2 hydrogen atoms per link

Polyvinyl chloride

produced if there is 1 carbon atom, 2 hydrogen atoms, and one polyvinyl chloride every other link

Polycinylidene chloride

produced if there is 1 carbon atom, 2 hydrogen atoms, and 2 chlorine atoms every other link

matter

composed of atoms

atoms

has a nucleus (containing protons and neutrons) and surrounded by a cloud of electrons

clouds of negative charge

what are electrons depicted as

Atomic Number (Z)

number of protons in a nucleus

Mass Number (A)

sum of the number of protons and number of neutrons in a nucleus

1.6605 x 10^-19

1 amu equal to in grams

1.007

mass of a proton in amu

+1.602 × 10^-19

charge of a proton

1.009

mass of a neutron in amu

neutral

charge of a neutron

0.00055

mass of an electron in amu

−1.602 × 10^-19

charge of an electron

isotopes

atoms of an element that differ in the number of neutrons in their nucleus

isotopic abundance

mass percentage of an isotope

mass spectrometers

measures the masses of atoms, isotopes, and molecules

atomic symbols

scientific shorthand way of writing information regarding atomic structure

relative atomic mass

average of the atomic masses for the isotopes of an element

ions

formed when number of protons and electrons are not equal

cations

ions with more protons than electrons

anions

ions with more electrons than protons

monatomic ion

ion derived from a single atom

polyatomic ion

ion derived from group of atoms with an overall charge

Coulombs’ Law

states that the force between ions is proportional to the product of the ion charges divided by distance squared

chemical formula

describes a compound in terms of the elements the compound contains

hydrates

water molecules associated with certain compounds

compounds

have different properties than their constituent atoms

ionic compounds

compound that contains cations and anions

molecular formulas

chemical formula that indicate the elements and the actual number of atoms contained

empirical formulas

chemical formula that indicate the smallest whole number ratio between number of atoms

chemical bonding

created by the exchange or sharing of electrons

ionic

bond that has exchange. cations and anions present

metallic

bond that shares by forming a mobile sea of electrons

covalent

bond that shares between atoms