Terms Flashcards
Chemical element:
A fundamental substance containing only one kind of atom
Mass number
of protons and neutrons in the nucleus
Atomic mass:
Atomic weight, average or relative.
Average: protons and different # of neutrons
Radio isotopes:
Give off energy in the form of alpha, beta, and gamma radiation from the nucleus (radioactive decay)
Molecule
A stable association of atoms of an element
Orbital
Region where an electron is found 90% of the time
Electron shells/energy levels
Chemical bond:
• Attractive forces holding atoms together
• Attractive force that links atoms together to form molecules
• A lasting attraction between atoms, ions, or molecules that enables the formation of a chemical compound
Covalent bonds:
Atoms share electrons. Each atom contributes an electron.
Compound bonds:
Pure substance made of two or more different elements bonded together in a fixed ratio.
Ionic bonds:
When one atom is much more electronegative than the other a complete transfer of electrons may occur
Ion:
Electrically charged particles formed when atoms lose or gain electrons.
Hydrogen bonds:
Attraction between the δ⁻ end of one molecule and the δ⁺ end of another molecule
Vander Waals forces:
Attraction between nonpolar molecules (compounds) that are close together (brief and weak)
Chemical reactions:
The making and breaking of chemical bonds - transforms substances
Energy:
The capacity to do work or the capacity for change.
Mole:
(unit) a name for a specific amount of substance
Mass of one mole: molecular weight of a compound (one mole) = sum of atomic weights of all atoms in a molecule
Cohesion:
Something that sticks to itself (surface tension)
Adhesion
Something that sticks to other things (capillary action)
Solution:
substance dissolved in liquid (solvent)
Homeostasis:
Living organisms maintain constant internal conditions
Monomers
Small molecules that bond together to form more complex structures
Polymer:
A long molecule consisting of many similar building blocks (monomers) and contain thousands more atoms
Functional group:
A specific group of atoms or bonds within a compound that is responsible for the characteristic chemical reactions of that compound