✔ P.1 Chemistry: Properties & Change Flashcards
anything that has mass and takes up space
matter
substance that cannot be broken down to other substances by chemical reactions
elements
substance consisting of 2+ different elements combined in a fixed ratio
compound
elements that an organism needs to live a healthy life and reproduce
essential elements
required by organisms in minute quantities
trace elements
basic unit of matter
atom
center of an atom, packed with protons and neutrons
atomic nucleus
same element, same # of protons, different # of neutrons (therefore different mass)
isotopes
- # of protons in an atom
- specific to each element
- abbreviated “Z”
atomic number
electrons that circulate the outer shell
valence electrons
atoms share/transfer electrons, the “glue” that attracts and keeps atoms held together due to sharing of each atom’s electrons
chemical bonds
2 or More atoms chemically bonded
molecule
making or breaking of bonds
chemical reactions
the starting molecules of a chemical reaction
reactants
the final molecules of a chemical reaction
products
subatomic particle located in the nucleus
protons and neutrons
All atoms of an element have the same number of protons, but may differ in the number of ____. Those atoms of the same element, but differ in the number of neutrons are called ______.
- Neutrons
- Isotopes
The chemical behavior of an atom is mostly determined by its ______.
electrons
Why is the shape of a molecule important in Biology?
- Key to its function in a cell
- Key to brain function
- How the receptors recognize the necessary molecule
- Think of opiates and endorphins
the energy associated with the relative motion of objects
kinetic energy
kinetic energy due to the random motion of atoms.
energy in its most random form
thermal energy
a measure in degrees of the average kinetic energy of the atoms and molecules in a body of matter
temperature
thermal energy in transfer from one body to another
heat
the amount of heat required to raise the temp of 1g of water by 1 degree C
calorie
a liquid, homogeneous mixture of 2 or more substances
solution
substance dissolved in a solution
solute
solution with water as the solvent
aqueous solution (aq)
scale used to express acidity and basicity of substances
pH
a solid that is produced as a result of a chemical reaction in solution
precipitate