Concepts for Day 1 Flashcards
from ChE Books
An unstable nucleus exhibits ___
radioactivity
nucleus contains essentially all the atom’s mass but
is only about ___
10^-5 its radius
identical to helium-4 nuclei
alpha particles
very high-energy photons
Gamma rays
high-speed electrons
Beta particles
one disintegration per
second (d/s)
becquerel (Bq)
number of disintegrations per
second in 1 g of radium-226
1 Ci = 3.7x10^10 d/s
proposed the technique of radiocarbon dating
Willard F. Libby
equal to 1 joule of energy absorbed per kilogram of
body tissue
gray (Gy)
discovered biochemical pathway using 14C in CO2
Melvin Calvin
substance that cannot be separated into simpler substances by chemical means
element
Molecules in a ___ are close together but are not held so rigidly in position and can move past one another.
liquid
It is the lowest temperature that can be attained theoretically
0 K
___ tells us how close a measurement is to the true value of the quantity that was measured
Accuracy
Precision
refers to how closely two or more measurements of the same quantity agree with one another
_____ the lightest elements that were the first elements formed in the early stages of cosmic evolution.
helium and hydrogen
He hypothesized that our universe burst into being billions of years ago in a gigantic explosion, or Big Bang.
George Gamow
A hydrogen atom has only one electron, which is stripped by the light from a quasar in a process known as
ionization
All substances, in principle, can exist in three states: solid, liquid, and gas. The interconversion between these states can be effected by _
changing the temperature
He formulated a precise definition of the indivisible building blocks of matter that we call atoms.
John Dalton
the ratio of electric charge to the mass of an individual electron is
-1.76x10^8 C/g
R. A. Millikan found the charge of an electron
to be
-1.60 x 10^19 C or 9.09x10^-28 g
Thomson proposed that an atom are embedded like raisins in a cake. This is so-called __
“plum-pudding model”
Its common name is milk of magnesia
Magnesium hydroxide
The most direct and most accurate method for determining atomic and molecular masses
mass spectrometry
The first mass spectrometer is developed by __ where it provided indisputable evidence of the existence of isotopes
F. W. Aston
reactant used up first in a reaction
limiting reagent
Reactants present in quantities greater than
necessary to react with the quantity of the limiting reagent.
Excess reagents
Phosphorus fertilizers are derived from phosphate rock, called
fluorapatite
Chemical name for aspirin
acetylsalicylic acid
considered electron-transfer reactions
oxidation-reduction, or redox reactions
refers to the half-reaction that involves loss of electrons
oxidation reaction
half-reaction that involves gain of electrons
reduction reaction
An easy way to predict whether a metal or hydrogen displacement reaction will actually occur
activity or electrochemical series
an element in one oxidation state is simultaneously oxidized and reduced
disproportionation reaction
there are about _____ in a kilogram of seawater.
1.3 g of magnesium
Gravimetric experiments often involve
precipitation reactions
commonly used poison is actually a white compound that dissolves in water, is tasteless, and if administered over a period of time, is hard to detect called
arsenic(III) oxide, As2O3
not superposable on its mirror image is said to be ___. An achiral object lacks chirality and has a superposable mirror image.
chiral; achiral
highly branched polysaccharide
Amylopectin
reserve carbohydrate of animals
Glycogen
skeletal polysaccharide of plants
Cellulose
