Unit 1 Flashcards
Protons=
positive
atomic number
in the nucleus
Electrons=
negative
atomic number
Neutrons=
neutral
in the nucleus
Atomic Mass
protons + neutrons
You go right on the periodic table
gets smaller, gain more electrons and protons so its a greater attraction force
You go down the periodic table
gets bigger, theres more electrons and protons BUT theres more orbits so it gets bigger
How many atoms of hydrogen are found in the sample of methane (2.71*10^23 particles CH4
1.08*10^24 atoms H
Isotopes
same number of protons as the normal element, but different number of neutrons. So they will have a different mass
Mass Spectrum
a graph that shows the different isotopes and how much is present
Relative abundance
tells us how common an isotope is in the sample.
Average atomic mass
(the relative abundance * mass) + (relative abundance * mass) + (relative abundance * mass)
ex- #85 has NA of 72.17% and mass of 84.912
#87 has NA of 27.83% and mass of 86.909 what is the third mystery element
hint make sure to move to decimal in the percentage (left)
One atom
ex- Mg
any
described as atom
More than one element (ionic)
ex- NaCl or Fe(NO3)2
Metal + Nonmetal
described as formula unit
More than one element (covalent)
ex- H2O or O2 or C6H12O6
Nonmetal +Nonmetal
described as molecule
Atom or group of atoms with a charge
ex- Pb2+ or SO4 2-
any
describes as ion
Compound
A substance compose of two or more elements united chemically in definite proportions.
Mixture
A combination of two or more substances in which each substance retains its own chemical identity.
Law of Constant Composition
A law that states that the elemental composition of a pure compound is always the same, regardless of its source; also called the law of definite proportions.
Heterogeneous Mixture
A mixture which does not have the same composition, properties, and appearance throughout.
Homogeneous Mixture
A mixture which has uniform composition, properties, and appearance throughout.
Solution
A mixture of substances that has a uniform composition; a homogeneous mixture.
Kelvin Scale
The absolute temperature scale; the SI unit for temperature.
Density triangle formula
M
D V
Precision
The closeness of agreement among several measurements of the same quantity; the reproducibility of a measurement.
consistency, reliable results, reproducibility
Accuracy
A measure of how closely individual measurements agree with the correct value.