Chemistry 105: Test One
electromagnetic radiation:
a source of light that can/cannot be seen
hypothesis:
a tentative explanation (educated guess)
How are ions formed?
by gaining or losing electrons
one hundredth of a gram:
centigram
ions:
charged particles; atoms with a net negative or positive charge
Positron
has the same mass as a beta particle, but a charge of 1+; ejected at 90% the speed of light; used in a medical radiation procedure called positron emission tomography
neutral atom:
has the same number of electrons and protons
Greek Prefix for 9
nona
Greek Prefix for 8
octa
Gamma Rays:
radio waves
one-thousandth of a meter:
1 millimeter
What is a beta particle?
a negatively charged particle ejected from the nucleus of a radioisotope; has the same mass and charge as an electron
alpha particle:
a particle with two protons and two neutrons
Greek Prefix for 10
deca
Mass Fomula:
density(volume)
Greek Prefix for 1
mono
Positron Particle:
positive electron
pico(p)
0.000000000001 = 10^-12
nano(n)
0.000000001 = 10^-9
micro(u)
0.000001 = 10^-6
milli(m)
0.001 = 10^-3
centi(c)
0.01 = 10^-2
deci(d)
0.1 = 10^-1
one billion meters:
1 gigameter
Which one is the greater amount of energy? 1kcal or 1kJ?
1 kcal = kilocal
mega(M)
1,000,000 = 10^6
giga(G)
1,000,000,000 = 10^9
kilo(k)
1000 = 10^3
deka(da)
10^1
Alpha particle:
2 protons + 2 neutrons
Which one is the greater amount of energy? 4.184 cal or 1J?
4.184 cal
Avogadro's number:
6.02 x 10^23 atoms or molecules
Diatomic atoms:
7 atoms that occur as homonuclear diatomic molecules (two) in their gaseous states: hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine. (start at atomic number 7 & make a 7 including hydrogen)
octet
8 valance electrons which creates a stable electron arrangement
Atomic symbol of Nitrogen:
N
Do all elements have isotopes?
NO
Atomic symbol of Nickel:
Ni
Atomic symbol of Palladium:
Pd
Iron
a trace element that transports oxygen from the lungs to different parts of the body and is also part of many enzymes and is essential for growth, healing, immune function and synthesis of DNA.
What is the difference between accuracy and precision?
accurate measurements fall near the true value while precise measurements are grouped together
Name the 4 types of radioisotopes:
alpha, beta, gama, and positron
What does each period on the periodic table represent?
an energy level
theory:
an experimentally explanation of an observed behavior
Matter:
anything that has mass and occupies space
Radioactive isotopes:
atoms that emit nuclear change
What is an isotope?
atoms with the same number of protons, but a different number of neutrons
how do atoms bond?
based on valance electrons
Why is most of the mass of an atom located in the nucleus?
because the mass is the number of protons plus the number of neutrons
An example of a chemical change (change is chemical composition) that involves starting with a liquid and ending up with a gas:
burning gasoline (combustion)
Physical changes that a piece of copper wire could undergo:
can be cut into smaller pieces, can be coiled into different shapes, can be melted using heat
Physical properties of a piece of copper wire:
can conduct electricity, is ductile, is malleable, is brown-gold in color, is shiny
Gas:
constantly moving; can be compressed; will take volume and shape of container
Greek Prefix for 2
di
Significant figures:
digits in a measurement that are reproducible when the measurement is repeated, plus the first uncertain digit
Gives an example of a substance that sublimes:
dry ice (solid carbon dioxide)
Gama Particle:
electromagnetic radiation
Beta Particle:
electron
skeletal structure:
electron dot structure
Bohr's atomic model:
electrons orbit the nucleus specific to the hydrogen atom; when energy is absorbed, the electron gets "excited" and jumps energy levels
trace elements:
elements that the body needs, but only in a limited amount
Law of conservation of energy:
energy is neither created or destroyed in an isolated system, it just changes from one form to another or transfers from one part of the world to another
Give an example of a physical change that involves starting with a liquid and ending up with a gas:
evaporation
Liquid:
fixed volume; will take shape of container (no fixed shape)
Ionic Compounds:
formed from metals & nonmetals; have a neutral charge; transfer/exchange electrons; written in their empirical formula
Anion
gain ions; negatively charged particle
Greek Prefix for 7
hepta
Name two trace elements:
iron and zinc
one millionth of a gram:
nanogram
Name and give the atomic symbols for the four most abundant elements in the human body:
oxygen (O), carbon (C), hydrogen (H), nitrogen (N)
Greek Prefix for 5
penta
Accuracy:
related to how close a measured value is to a true value
Specific gravity:
relates the density of a substance to that of water
is the statement "what goes up must come down" a scientific law or a scientific theory? Explain.
scientific law; scientific laws are statements that describe things that are consistently & reproducibly observed
Periodic Table Group Family:
share in both chemical and physical properties
What are the three states of matter?
solid, liquid, gas
Specific gravity formula:
specific gravity = density of substance/density of water
Greek Prefix for 4
tetra
Energy:
the ability to do work and transfer heat
Physical change:
the chemical composition of matter is not altered
Deposition:
the conversion of a gas directly into a solid (reverse process of sublimation)
Sublimation:
the conversion of a solid directly into a gas (w/o becoming a liquid)
Adequate Intake (AI):
the daily intake of a nutrient believed to be sufficient to meet the needs of people (due to unreliability of experimental data, the percentage of people covered by a particular AI is uncertain)
Recommended dietary allowances (RDA):
the daily intake of nutrients that are sufficient to meet the needs of 97%-98% of healthy people
What are the two parts to scientific notation?
the decimal part and the exponential part
Kinetic energy:
the energy of motion
Heat of vaporization:
the heat required to evaporate a liquid
Heat of fusion:
the heat required to melt a solid
molar mass:
the mass in grams of one mole of atoms of the element; equal to its atomic weight in amu
Why does the nucleus of an atom have a positive charge?
the nucleus is made up of protons (+) and neutrons (O) so the overall charge is positive (+)
Atomic number:
the number of protons in an atom's nucleus
nuclear radiation:
the particles & energy released in a nuclear change
Mass number:
the total number of protons and neutrons in an atom's nucleus
ROY G BIV
the visible spectrum (colors we CAN see)
Cation
lose electrons; positively charged ion
Polyatomic Ions:
many atoms that come together with the same charge
How do you get the estimated mass of an element?
mass of the isotope X percent abundance + every isotope present
Volume Formula:
mass/density
Density Formula:
mass/volume
Solid:
matter is closely packed together; fixed volume; fixed shape
one million grams:
megagram
Binary/Covalent compounds:
molecular/covalent; formed from two nonmetals or a nonmetals and a metalloid; share electrons; form covalent bonds
one million meters:
1 megameter
hecto(h)
100 = 10^2
Molecule:
collection of atoms
Atomic symbol of Sulfur:
S
Precision:
a measure of reproducibility
Greek Prefix for 6
hexa
Potential energy:
stored energy
How is an alpha particle similar to a helium nucleus?
they are identical because both have two protons, two neutrons, and a 2+ charge
Zinc
trace element that forms enzymes and improves immune function, helps clot blood, maintains sense of taste and smell, keeps skin healthy and enables normal growth and development.
Greek Prefix for 3
tri
infrared
type of light that WE give off
How is a beta particle different than an electron?
unlike an electron, a beta particle is ejected from the nucleus of a radioisotope at up to 90%. the speed of light; the mass of a beta particle is equal the mass of an electron; the charge of a beta particle is 1+
Atomic symbol of Gold:
Au
Atomic symbol of Xenon:
Xe
How are positrons and beta particles different?
a beta particle has a charge of 1- while a positron has a charge of 1+
How is a theory different from a hypothesis?
a hypotheis is made based on observations or currently known facts, while a theory is an experimentally explanation of an observed behavior. If a hypothesis survived repeated testing, it may become a theory (theories explain while hypothesis are a tentative explanation)
