chem Flashcards
How ar elements represented in the periodic table in terms of valence shells
the amount of molecules in the shells represents what place they are in the periodic table and how many spaces they have open for bonding
what are three parts of an atom and its charges
neutrons-neutral, protons-positive, electrons-negative
hwo is atomic number determined
by the number of proton
how is atomic weight determined
protons plus neutrons
how can the same element have different atomic mass
if they are isotopic, meaning that the number of neutrons differ
why don’t atoms gain electrons or neutrons to get charge
the it’ll be a different element
why do elements get charged
to gain or lose electrons and become more stable
a charged particle is called an___
ion
which side of the periodic table is positively and negatively charged and why
the left side is positive while the right side is negative, this happens so that opposites attract each other
why is carbons ability to form double and triple bonds important
it allows for a lot variety and ability to make complex molecules
why cant silicone be used to make organic bases instead of carbon
silicone is not as stable as carbon
what does every line between atoms represent in a molecule
a bond
how many spaces does hydrogen have left to bond, as well as oxygen and nitrogen
hydrogen, oxygen-2, nitrogen-3
ionic vs covalent bond
ionic=formed by ions, covalent=formed by charing electrons
what is a buffer
a compound that minimizes the changes in pH
what does pH measure
how acidic or basic something is
why is water good at dissolving polar molecules but not nonpolar molecules
water doesn’t dissolve nonpolar molecules becasue they arent fully charged, making the water and the molecules oppositely charged
which molecules make the best buffers
hydrogen and nitrogen
what are 5 traits of water and why are they important
adhesion, cohesion, ice density, high specific heat, and universal solvent
allows it to binds with itself, makes it stick to surfaces, keeps homeostasis, dissolves compounds quickly
what are valence electrons
the outermost shell of an atom
what are covalent bonds
the sharing of electrons between atoms
how is ph logarithmic
the units of pH differ by 10x either positively or negatively each time you increase or decrease by one unit
how does hydrogen affect the properties of water
hydrogen makes water stick to each other and makes it adhere to other surfaces
how can you tell if something is basic or acidic
anything that has a pH level under 7 is acidic while anything with a pH level over 7 is basic
