Chemistry Exam Review 2
Terms
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- Allotrope
- one of two or more different molecular forms of an element in the same physical state
- Barometer
- an instrument used to measure atmospheric pressure
- Sublimation
- the conversion of a solid to a gas or vapor without passing through the liquid state
- Calorie
- the quantity of heat that raises the temperature of 1 g. of pure water 1 degree C
- energy
- the capacity for doing work; it exists in several forms, including chemical, nuclear, electrical, radiant, mechanical, and thermal energies
- Aplitude
- the height of a wave from the origin to the crest
- frequency
- (v) the number of wave cycles that pass a given point per unit of time; there is an inverse relationship between the frequency and wavelength of a wave
- photon
- a quantum of ligh; a discrete bundle of electromagnetic energy that behaves as a particle
- wavelength
- the distance between two adjacent crests of a wave
- vaproization
- the converstion of a liquid to a gas or a vapor
- boiling point
- the temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid
- triple point
- the point on a phase diagram that represents the only set of conditions at which all three phases esist in equilibrium with one another
- crystal
- a substance in which the atoms, ions, or molecules are arranges in an orderly, repeating, three-dimensional pattern called a crystal lattice
- unit cell
- the smallest group of particles within a crystal that retains the geometric shape of the crystal
- quantum
- the amount of energy needed to move an electron from its present energy level to the next higher one
- What is the first part of the kinetic theory of gases?
- Gas is composed of small particles with no attractive/repulsive forces between them
- What is the second part of the kinetic theory of gases?
- Particles move in constance, random motion
- What is the third part of the kinetic theory of gases?
- All collisions are perfectly elastic (no energy is lost)
- SI unit for pressure
- pascal (Pa)
- SI unit for Temperature
- Kelvin (K)
- SI unit for frequency
- Hertz (Hz)
- Endothermic reaction
- absorbs heat
- Exothermic reaction
- gives off heat
- Dalton's model of the atom
- Solid indivisible mass
- Thomson's model of the atom
- "plum pudding" mode; electrons stuck into mass of positive charge
- Rutherford's model of the atom
- nuclear mode; atom mostly empty space, with small positive charge in center
- Bohr's model of the atom
- Planetary mode; electrons found in energy levels around nucleus
- Quantum mechanical model of the atom
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1. Modern description of electrons
2. No exact path of electrons around nucleus; estimates probability of finding electron in certain position - Avogadro's hypothesis
- Equal volumes of gases at the same temperature and pressure contain equal numbers of particles
- Heisenberg Uncertainty Principle
- We cannot know 1. position or 2. velocity of particle at the same time
- Photoelectric effect
- Metals eject electrons when light shines on them