|
Matter |
which is anything that takes up space and has mass |
|
element |
is a substance that cannot be broken down to other substances by chemical reactions |
|
compound |
is a substance consisting of two or more different elements combined in a fixed ratio |
|
essential elements |
of 92 natural elements, about 20-25% are ______ that an organism needs to live a healthy life and reproduce. |
|
CHON (Carbon, Hydrogen, Oxygen, Nitrogen). |
which elements make up 96% of living matter? |
|
Ca, P, K, S (Calcium, Phosphorus, Potassium, Sulfur) |
which other elements make up the remaining 4% of an organisms mass? |
|
Trace Elements |
required by an organism in only minute quantities. |
|
Fe (Iron), and I (Iodine) |
What are the other trace elements? |
|
atom |
is the smallest unit of matter that still retains the properties of an element. |
|
subatomic particles |
tiny bits of matter are composed of these smaller parts |
|
neutrons |
electrically neutral |
|
protons |
1 unit of a positive charge |
|
electrons |
1 unit of negative charge |
|
atomic nucleus |
protons and neutrons are packed together tightly in a dense core, at the center of an atom, called_____. |
|
Mass number |
number of protons + neutrons |
|
dalton |
unit of measurement used for protons and (neutrons is the mass used for the elements.) |
|
atomic number |
subscript to the left of element symbol and = number of protons or = number of electrons in a NEUTRAL atom |
|
number of neutrons |
= mass number – atomic number |
|
isotopes |
different atomic forms of the same element, having more neutrons than protons and therefore have a higher mass |
|
radioactive isotope |
is one in which the nucleus decays spontaneously, giving off particles and energy. |
|
radioactive tracers |
used as diagnostic tools in medicine. |
|
radiometric dating |
when scientists measure the ratio of different isotopes and calculate how many half- lives in years have passed since an organism was fossilized or a rock was formed. |
|
half-life |
of the isotope, the time it takes for 50% of the parent isotope to decay |
|
Energy |
the capacity to cause change (by doing work) |
|
potential energy |
energy that matter possesses because of its location or structure. |
|
electron shells |
concentric circles, characteristic average distance and energy level |
|
the closer the electrons are to the nucleus … |
the lower the potential energy |
|
the farther the electrons are from the nucleus… |
the higher the potential energy and the farther away the electron shells are |
|
negative electrons are attracted to… |
positively charged protons |
|
valence electrons |
number of electrons in the outermost shell |
|
valence shell |
the outermost electron shell |
|
Reactive elements |
have 7 or 1 electrons in the valance shell |
|
inert elements |
have a full valence shell =8, they do not interact |
|
orbital |
three dimensional space where an electron is found 90% of the time is called |
|
covalent bond |
(Strong) is the sharing of a pair of valance electrons by two atoms. |
|
molecule |
when two or more atoms are held together by covalent bonds |
|
molecular formula |
H2 |
|
lewis dot structure |
the element symbol is surrounded by dots representing the valance electrons (H:H) |
|
structural formula |
H–H where the line represents a single bond |
|
ball-and-stick models |
… |
|
double bond |
sharing of 2 pairs O=O |
|
valance |
the bonding capacity |
|
electronegativity |
the attraction of a particular atom for the electrons of a covalent bond is called… |
|
non-polar |
electrons are shared equally, and there is an equal pull on electrons (carbon and hydrogen for example) |
|
polar covenant bonds |
unequal sharing/electronegativity, stronger pull by one partner, partial charge, example hydrogen and oxygen |
|
ions |
extreme difference in electronegativity, when one strips an electron from the other it becomes this… |
|
cation |
positively charged ion, (had an electron stripped away and needs one–ex: sodium 11 protons and 10 electrons-pos charge) |
|
anion |
negatively charged ion, that has received an extra electron (ex: chlorine 17 protons + 18 electrons leaving it with a negative charge) |
|
ionic bond |
when 2 oppositely charged ions attract, they form an ionic bond or an ionic compound (NaCl) |
|
Ionic compound |
compounds formed by an ionic bond |
|
hydrogen bond |
weak bond, attraction between hydrogen and electronegative atom is called… |
|
van der waals interactions |
occurs when molecules are close together, not always evenly distributed, shifts overtime, and powerful when there are a lot of them. |
|
reactants |
starting materials before a chemical reaction |
|
products |
the end result of a chemical reaction |
|
chemical equilibrium |
the point at which the reactions offset one another exacrly |
|
element |
A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) _____. isotope proton molecule compound element |
|
protons |
Changing the number of _____ would change an atom into an atom of a different element. |
|
molecule |
two or more atoms held together by covalent bonds. |
|
are different ions |
Atoms with the same number of protons but with different electrical charges _____. |
|
an attraction between ions of opposite charge |
An ionic bond involves _____. |
|
lowering EA. |
Catalysts speed reactions mainly by … |
|
mono- |
single |
|
di- |
two |
|
non- |
not |
|
tri- |
three |
|
iso- |
equal |
|
anti- |
against |
|
co- |
together |
|
poly- |
many |
|
quad- or quat- |
four |
|
prim- |
first |
|
hydro- |
water |
|
ad- |
to |
|
neutr- |
of neither gender or type |
|
-phob |
to fear |
|
-phil |
to love |
|
-lysis |
loosening, split apart |
|
proto- |
first |
|
lip- |
fat |
|
de- |
from, out of, remove |
Share This
Flashcard
