matter and energy

Matter and EnergyBreaking it down and reviewing old

material.

Matter – anything that occupies space and has mass.

Matter can be found in the form of elements (distinctive building blocks) and compounds (two or more elements bonded together).

Various elements, compounds, or both can be found in mixtures.

Saltwater? Silver bar? Table salt?

What are Nature’s “building blocks”?

Matter is found, essentially, in three states:◦ Solid – atoms arranged in close proximity.◦ Liquid – atoms arranged in a more dispersed

pattern.◦ Gas – atoms widely spaced.

Phases of Matter

Atoms – the smallest component of an element displaying all characteristics of that element.

Sub-atomic particles – ◦ Protons – found in nucleus, + charge, 1 AMU◦ Neutrons – found in nucleus, no charge, 1 AMU◦ Electrons – found orbiting nucleus, - charge,

approximately 1/1836 AMU

Atoms, Ions, and Isotopes

Ions – charged atoms due to having gained or lost electrons.

Why do ions form? Examples of ions? Isotopes – atoms with the same atomic

number but different atomic mass. Why the difference in mass? Examples of isotopes?

Ions and Isotopes

Ionic compounds are compounds made up of oppositely charged ions.

The classic example would be table salt (NaCl).

Covalent compounds are formed from uncharged atoms.

The classic example would be water (H2O).

Bonds

Based on carbon atoms bonded with one or more other elements, such as: hydrogen, oxygen, nitrogen, sulfur, phosphorus, chlorine, and fluorine.

Types of organic molecules include:◦ Hydrocarbons – CH4, C8H18

◦ Chlorinated hydrocarbons – DDT, PCBs◦ Chlorofluorocarbons – CFCs◦ Simple carbohydrates – C6H12O6

Simple Organic Compounds

Composed of polymers of simple organic molecules.

Examples include:◦ Complex carbohydrates – formed from simple

carbohydrates◦ Proteins – formed from amino acids◦ Lipids – formed from excess carbohydrates◦ Nucleic acids – formed from nucleotides◦ Genes – composed of specific sequences of

nucleotides in a DNA molecule◦ Chromosomes – combinations of genes

Complex Organic Molecules

Basically, everything else. Stuff like H2, CO2, O2, O3, NaCl, NaOH, N2,

N2O, NO, NH3, H2SO4

Inorganic Compounds

A measure of how useful a matter resource is, based on availability and concentration.

High-Quality Matter is organized, concentrated, usually found near the surface of the Earth, and has great potential as a matter resource.

Low-Quality Matter is disorganized, dilute, usually found deep in the Earth or oceans, and has little potential use as a resource.

Matter Quality

The ability to do work (and transfer heat). Forms of energy –

◦ Light◦ Heat◦ Electricity◦ Chemical◦ Mechanical◦ Nuclear

Energy

Potential – stored and contingent on position.◦ Height◦ Chemical◦ Nuclear forces

Kinetic – contingent on mass and velocity.◦ Heat◦ Temperature◦ Electromagnetic Energy

Energy Classification

Like Matter Quality, Energy Quality is dependent on how useful it is to us.

High-Quality Energy –◦ Gasoline◦ Sunlight◦ Uranium nuclei

Low-Quality Energy –◦ Heat in the atmosphere or oceans◦ Waste heat

Energy Quality

Conservation of Matter – there is no “away”. While we utilize resources and seem to

“consume” matter, we are really doing nothing more than rearranging the atoms involved.

It’s not just a good idea, it’s the Law(s)!

1st Law – In all physical and chemical changes, energy is neither created nor destroyed, but it may be converted from one form to another.

2nd Law – When energy is converted from one form to another, some of the useful energy is always degraded to lower-quality, more dispersed (higher entropy), less-useful energy. Entropy is a measure of disorder. Therefore, it is always increasing. “Entropy always wins.”

3rd Law – The entropy of a perfect crystal at absolute zero is exactly equal to zero.

Zeroth Law – if two systems are both in thermal equilibrium with a third, then they are in thermal equilibrium with each other.

The Laws of Thermodynamics

Physical – involves no change in chemical composition. Examples include splitting wood, mixing cake batter ingredients, and shaping metal.

Chemical – involves a change to the chemical composition of a substance. Examples include burning wood, baking cake batter, and metal rusting.

Nuclear – certain isotopes are so unstable they are able to spontaneously rearrange themselves and form new isotopes. These processes are known as radioactive decay, fission, and fusion.

Matter Changes

Radioactive decay occurs when unstable isotopes rearrange their nuclei and release bursts of energy in the form of high-energy particles that are ionizing.

As they rearrange themselves, they become a different, more stable isotope at a predictable rate.

The amount of time it takes for 50% of a substance to naturally degrade to a stable isotope is expressed as its “half-life”.

Radioactive substances are deemed to be safe after 10 half-life cycles.

Nuclear Changes

Potassium-42 – 12.4 hours Iodine-131 – 8 days Cobalt-60 – 5.27 years Tritium – 12.5 years Strontium-90 – 28 years Carbon-14 – 5,370 years Plutonium-239 – 24,000 years Uranium-235 – 710 million years Uranium-238 – 4.5 billion years

Typical half-life periods

Large, unstable isotope nuclei are struck by neutrons and split into smaller nuclei.

When these nuclei split, energy and additional neutrons are release.

A chain reaction will occur as long as sufficient additional nuclei are present.

Nuclear Fission

Two light elements, usually hydrogen isotopes, are combined to form a larger atom.

D-T = 100 million Co

D-D = 1 billion Co

Nuclear Fusion

High-throughput (high-waste) societies attempt to avoid the impact of the 2nd Law of thermodynamics by utilizing increasing amounts of energy and matter to sustain themselves. Ultimately, they are unsustainable.

Matter-recycling societies attempt to mitigate their impact through recycling efforts. The amount of energy becomes the limiting factor.

Low-waste societies are sometimes referred to as Earth-wisdom societies and attempt to live in equilibrium with matter and energy resources available.

Finally, Societies