### substance | atom:

Radioactive atom
* Some radioactive atoms give alphas and some betas.
* decay at a certain rate
  - into stable atoms by a simple mathematical process
  - randomly
* emit ionizing radiation as they decay
  - three different kinds of radiation
* give off particles and change into different types of atoms.
* have surplus energy and are unstable
  - unstable nuclei
* liberate energy while disintegrating.
* produce radiation as they disintegrate.
+ Half-life (element): Nuclear physics
  * Radioactive atoms have unstable nuclei. Their nuclei are unstable because the arrangement of protons and neutrons in them are unsteady, making them shake until that they begin to decay and change into completely different types of atoms by releasing certain types of radioactive particles, such as alpha particles, beta particles or gamma rays, and possibly by fissioning into smaller nuclei. This is known as radioactive decay.

Sodium atom
* combine with atoms
  - chlorine atoms
* have shells
  - valence shells

Stable atom
* have lower energy than unstable ones.
+ Chemical stability: Chemistry
  * When an atom has an extra electron or a missing electron, it is unstable. When that atom loses or gains the electron, it becomes stable. Stable atoms have lower energy than unstable ones.

Unstable atom
* Some unstable atoms cause damage.
* differ from stable atoms because they have an excess of energy or mass or both.

Auxin
* migrates to the dark side of a stem and the stem elongates more on that side.
* promotes lateral root initiation but inhibits root elongation.

Baleen
* Most baleens swim with their mouths open, letting the water and nutrients come through.
* are migratory whales.
* look like the teeth of a comb.

### substance | ballast:

Electronic ballast
* Most electronic ballasts use instant-start technology that eliminates the flashing.
* are a proven technology, used in all new buildings today
  - far more efficient than older, magnetic ballasts
  - high-frequency versions of standard magnetic core and coil ballasts
  - kinder to lamps
  - major components in fluorescent light fixtures
  - more expensive than electromagnetic ballasts
* can also produce energy savings which can results in dollar savings.
* increases energy efficiency.
* offer greater lamp efficacy than magnetic ballasts, but are more expensive.
* provides instant-on, flicker free light and lasts for up to five years.
* regulate voltage using solid-state components rather than a magnetic core.
* start and regulate fluorescent lamps with the use of electronic components.

### substance:

Basalt
* All basalts show normal magnetic inclinations.
* Many basalts contain phenocrysts of olivine, plagioclase feldspar and pyroxene
* Most basalts absorb heat
  - have thickness
* Some basalt contains light-colored crystals.
* Some basalts are intrusive having cooled inside the Earth's interior
  - cause extinction
  - contain sodium
  - have crystal
* act as paleo-compasses.
* are dark colored, fine-grained extrusive rock
  - dark-colored rocks solidified from molten lava
  - igneous rocks
  - thus dark in color
  - volcanic rocks
  - volcanic, micro-crystalline rock
* contain minerals like olivine, pyroxene and plagioclase, none of which contain water.
* currently weather to iron-rich red soils.
* erupt non-explosively, indicating a low gas content and therefore low water content.
* flows and volcanic cones form in southwestern Utah
  - from fissure eruptions created much of the volcanic field
  - typically erupt very quietly and predictably
* form on Earth when volcanos erupt throwing out molten rocks into the air or the sea.
* frequently weather to red soils due to present of iron.
* make up most of Earth's oceanic crust
  - oceanic crust and only mantle underlies crust
* tend to be light to medium gray.
* vary from porphyritic to massive, non-porphyritic.