FSE1105 Thanatochemistry Chapter 4

Reactions of Elements - Oxidation

Addition of Oxygen to another substance

Halogens

Cl, F, Br, I are used as disinfectants. Chlorine, Bromine, Flourine, Iodine. All 4 are Diatomic in nature Cl2, F2, Br2, I2

Metals

Generally said to conduct heat and electricity. They have a luster ( shine ), reflect light, some are ductile ( made into wire ), some are malleable ( hammered into sheets ), and some have a high tensile strength. most are solids, but mercury is liquid. metals found on left side of periodic table.

Nitrogen

Most abundant element in Air Forms essential compounds of the human body Diatomic in nature N2

Oxygen

Most abundant element on Earth Diatomic in nature O2 Oxides are compounds that contain Oxygen

Non-metals

Not good conductors of heat or electricity. usually brittle, not malleable, and generally not ductile. some non-metals are solids, others liquids and still others are gases at room temp.

Reactions of Elements - Reduction

Removal of Oxygen from another substance

Hydrogen

Smallest, lightest element in existence Diatomic in nature H2 Nascient (Nascent) form H Most abundant element in universe first element to appear on periodic table. element which is in its gaseous state at room temp. Hydrogen atoms contain one proton and one electron. do not normally contain neutrons.

Noble Gases

Tend not to react with any other elements

Diatomic Elements

There are 7 elements that are diatomic in nature, that means they exist in pairs in nature. They will normally be observed in this pair. If they exist as a single atom of the element, they are called Nascent. The elements are H2, O2, N2, Cl2, F2, Br2, & I2

Oxidation and Reduction

These two reactions occur at the same time. That is, as one substance (compound) gives up oxygen, another one takes it in. These reactions are called REDOX reactions, because they have both Reduction and Oxidation at the same time. The book lists the various definitions for Oxidation and Reduction, please remember the electron definition and that is OIL RIG. Oxidation Is Loss of electrons - Reduction Is Gain of electrons

Types of Oxidation - Spontaneous combustion

the explosion caused by the unvented accumulation of heat produced by the slow oxidation of organic substances. the sudden explosion of grain silos is an example.

Types of Oxidation - Rapid

the oxidation of a substance at a relatively high temperature. the burning of wood is an example. rapid oxidation occurs when the kindling point of a substance is reached. the kindling point of a substance is that temperature at which a substance bursts into flames, producing heat and light. also referred to as combustion.

Types of Oxidation - Slow

the oxidation of a substance at a relatively low temperature. the rusting of metal is an example

Types of Oxidation - Decay

the slow oxidation of organic matter caused by aerobic bacteria.

Types of Oxidation - Putrefaction

the slow oxidation of organic matter caused by anaerobic bacteria