Chapter 2 Flashcards
(29 cards)
Major elements that make up 96% of our mass
Oxygen
Carbon
Hydrogen
Nitrogen
Isotopes
Atoms of an element that have different numbers of neutrons
Radioactive isotopes
Unstable isotopes that spontaneously change into a stable configuration
Ions
If an atom gives up or gains an electron it becomes an ion
Anion
A negatively charged ion
Cation
A positively charged ion
Molecule
If two or more atoms share electrons, they are called a molecule
Compound
A substance that contains atoms of two or more different elements
Ex NaCl
Free radicals
An atom or group of atoms with an unpaired electron in the outermost shell
Chemical bonds
Forces that hold atoms together
Ionic bonds
Are formed when one atom gives up an electron to another atom
Covalent bonds
Formed when 2 or more atoms share electrons - neither gives an electron away or takes an electron
Nonpolar covalent bond
Equal custody of the electron
Polar covalent bond
The sharing is unequal
Hydrogen bonds
Formed when a hydrogen atom with a partial positive charge attracts a partial negative charge of a nearby electronegative atom
Energy
The capacity to do work
Potential energy
Energy stored by matter
Kinetic energy
Energy associated with matter in motion
Chemical energy
A form of potential energy stored in bonds of compounds and molecules
Exergonic reactions
Release more energy than they use
Endergonic reactions
Absorb more energy than they release
Synthesis reactions - anabolism
2 or more atoms, ions, or molecules combine to form new and larger molecules
Decomposition reactions - catabolism
A large molecule is split into smaller atoms, ions, or molecules
Oxidation reduction reactions
Essential to life
Break down food molecules to produce energy
