section 1
what are the branches of chemistry?
what are the types of research?
organic chemistry, inorganic chemistry, physical chemistry, analytical chemistry, biochemistry, theoretical chemistry
basic research, applied research, technological development
what is the order for the 5 scientific methods: law, theory, experiment, hypothesis, observation
1. observation
2. hypothesis
3. experiment
4. theory
5. law
what is the definition of an atom?
basic unit of an element
what is a wavelength and frequency?
wavelength - the distance between any given point and the same point in the next wave cycle
frequency - the number of events per unit of time where an event is repeating at regularly spaced time intervals
what are the 3 bonds?
ionic bonds, covalent bonds, metallic bonds (also known as sea of electrons)
what are some properties of matter?
volume, mass, amount of energy, boiling point, melting point, density, ability to conduct electricity
SI (international system) or metric
what is an isotope? what are the 3 isotopes of hydrogen?
isotope - atoms with the same number of protons but different numbers of neutrons
hydrogen - tritium, deuterium, protium
what is a photon
a tiny particle that comprises waves of electromagnetic radiation; quanta light energy
formula: E = h f
what is bond length?
the distance between the centers of two covalently bonded atoms
what is chemical change and physical change?
chemical change - a change in which one or more substances are converted into different substances
physical change - a change in substance that does not involve a change in the identity of the substance
what are the 7 base SI units
ampere, candela, meter, kilogram, second, kelvin, mole
what is average atomic mass?
number underneath the abbreviation for element
what is ionization energy and energy affinity?
ionization energy - the amount of energy required to remove an electron from an isolated atom or molecule
energy affinity - amount of energy released when an electron is added to a neutral atom
what is VSEPR theory?
model used to predict 3-D molecular geometry based on the number of valence shell electron bonds
what is the third name for metalloids, also known as poor metals?
semimetals
what is the difference between accuracy and precision
accuracy - getting close to a known standard, close to the answer
precision - consistent with answers
what is a mole?
unit of measurement for amount of substance
what does the universe want?
low energy, high stability
size of nucleus, density, electrons in electron cloud
what is the difference between heterogeneous and homogeneous?
heterogeneous - not uniform throughout
homogeneous - uniform in composition
what is inversely proportional and directly proportional?
inversely proportional - one goes up, the other goes down; hyperbola
directly proportional - one goes up, so does the other; linear
what is molar mass?
defined as the ratio between the mass and the amount of substance
how many valence electrons in group 1?
1 valence electron
what did the cathode ray discover?
discovery of electron; electrons are small and negatively charged; moving charges will deflect in a magnetic field; cathode to anode = negative