Chapter 4 & 5 Flashcards
Element
Pure substance that can’t be broken down into other substances by any means
Matter
Anything that occupies space and has mass
Elements essential for life
CHNOPS Carbon Hydrogen Nitrogen Oxygen Phosphorus Sulfur
Trace element
Element critical to health that makes up less than 0.01% of body mass
Compound
Substance containing two or more elements chemically combined in a fixed ratio
Atom
Smallest particle of an element
Isotope
One of several forms of an element, each containing the same number of protons but different number of neutrons.
Radioactive isotope
Isotope in which in the nucleus decays over time, giving off radiation in the form of matter and energy
Ionic bond
Chemical bond that occurs when an atom transfers an electron to another atom
Ion
Atom that has become electrically charged as a result if gaining or losing an electron
Covalent bond
Chemical bond that forms when two atoms share electrons
Molecule
Two or more atoms held together by covalent bonds
Chemical reaction
Breaking of old and formation of new chemical bonds that result in new substances.
Reactants
Starting material for a chemical reaction
Product
Material created as a result if a chemical reaction.
Polar molecule
Molecule in which opposite needs have opposite electric charges
Hydrogen bond
Bond created by the weak attraction of a slightly positive hydrogen atom to a slightly negative portion if another molecule
Cohesion
Tendency of molecules of the same kind to stick to one another
Adhesion
Attraction between unlike molecules
Thermal energy
Total energy associated with the random movement of atoms and molecules
Temperature
Measure of the average energy of random motion of particles in a substance
Solvent
Substance in a solution that dissolves the other substance and is present in the greater amount.
Solute
Substance in a solution that is dissolved and is present in a lesser amount.
pH scale
A range of numbers used to describe how acidic or basic something is (0 acidic- 14 basic)
Acid
Compound that donates H+ ions to an aqueous solution and measures less than 7 on the pH scale
Base
Compound that removes H+ ions from an aqueous solution and that measures more than 7 on the pH scale
Buffer
Substance that maintains a fairly constant pH in a solution by accepting H+ when their levels rise and donating H+ ions when their levels fall
Organic molecules
Carbon based molecule
Hydrocarbon
Organic molecule composed of only carbon and hydrogen atoms
Inorganic molecule
Non carbon based molecule
Functional group
Group of atoms within a molecule that interacts in predictable ways with other molecules
Hydrophilic
Attracts water molecules