The smallest building block of matter
Atom
An envelope of gasses surrounding the planet
Atmosphere
Anything that has mass and takes up space
Matter
Cannot be broken down into simpler forms by chemical means
Elements
Whenever energy is converted from one form to another in a physical or chemical change
1st Law of Thermodynamics
How matter is passed from one organism to another and from one part of the biosphere to another
Biochemical Cycles
Two or more different elements held together in fixed proportions
Compounds
A single nutrient that is scarce or cycles slowly, limiting the ecosystem
Limiting Nutrient
The process when other bacteria convert nitrates into nitrogen gas
Denitrification
The total number of neutrons and protons in an atom’s nucleus
Mass Number
When energy is changed from one form to another, it always results in less high-quality energy
2nd Law of Thermodynamics
A combination of two or more atoms of the same or different elements held together by chemical bonds
Molecule
Physical or Chemical changes can take place in chemical reactions, but no atoms are created or destroyed in the process
Law of Conservation of Matter
Consists of the parts of the atmosphere, hydrosphere, and geosphere where life exists
Biosphere
The number of protons in an atom’s nucleus
Atomic Number