Chemistry Flashcards
What is Matter
Any physical substance that has mass and occupies space.
Elements
Fundamental Substances that cannot be created or broken down by ordinary chemical means
- 118 total
Primary elements of the human body
Oxygen (O) - 65%
Carbon (C) - 18%
Hydrogen (H) - 9.5%
Nitrogen (N) - 3%
and 22 others…
Atom
smallest unit of an element that retains the unique properties of that element.
Valence Shell
Outermost shell of an atom
Octet Rule
the tendency of atoms to prefer to have eight electrons in the valence shell. When atoms have fewer than eight electrons, they tend to react and form more stable compounds.
Atomic number
- Number of protons in an atom’s nucleus.
- Identifies the element.
isotope
one of the variations of an element in which the number of neutrons differ from each other
radioisotopes
unstable, heavy isotope that gives off subatomic particles, or electromagnetic energy, as it decays; also called radioactive isotopes
molecule
2 or more atoms covalently bonded together
(chemical) compound
substance composed of two or more different elements joined by chemical bonds
Free Radicals
an atom, molecule, or ion that has at least one unpaired valence electron. With some exceptions, these unpaired electrons make radicals highly chemically reactive. Produced by oxidation.
Antioxidants
compounds that inhibit oxidation,
Acids
Compounds that release Hydrogen (H+) ions in solution.
ionic bond
An attraction between an anion and a cation
covalent bond
A chemical bond in which who atoms share electrons, thereby completing their valence shells
Hydrogen Bonds
dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom
ion
An atom with an overall positive or negative charge
cation
ion with a positive charge
anion
ion with a negative charge
Lipids
Class of nonpolar organic compounds built from hydrocarbons and distinguished by the fact that they are not soluble in water.
