Flashcards in C16 Terms Deck (45)
law of definite proportions
Established that masses if chemical substances combine in definite repeatable ratios
Based on the caloric theory
Atoms are masses that have a positively charged (pudding) in which the negatively charged electrons stay
Every atom has a nucleus and electrons circle around it
Electrons circle around the nucleus
Electrons move in waves around the nucleus
Subregions of space
Neutrons and protons in the nucleus
Subatomic particles that are the building blocks of photons neutrons and electrons
atomic number (Z)
The number of protons in the nucleus
Aims of elements that have different numbers of neutrons
Tells isotopes apart
Shows both the atomic and mass numbers of the element
The mass of an electron expressed in atomic mass units
atomic mass unit (u)
The mass equal to 1/12th the mad of a carbon atom
Represent the regions where an electron with a certain amount of energy is most likely to be found.
Is the arrangement of the energy levels and the positions that electrons can take within those energy levels for a given number of electrons.
The electrons in the outermost energy level
The study of changes in atomic nuclei
The emission of nuclear radiation
The rays and particles emitted by unstable nuclei
Positively charged particles
Negatively charged particles
A nucleus shedding energy by releasing gamma rays
The atoms nucleus loses two protons and two neutrons
The atom loses a beta particle and emits gamma rays
radioactive dating technique
Using nuclear decay to date things
nuclear bombardment reaction
When a nucleus is stuck by a high energy particle
The splitting of an atom
When one atom after another is broken apart
The crushing of two atoms to form a larger atom
What is the most important aspect of a scientific model?
It has to work
Discuss one aspect of John Dalton's atomic model that was set aside by a later discovery.
The core envelope model was based on the caloric theory
What was the most significant question about the atom after Thomson's discovery of the electron?
The extra mass that was measured
What phenomenon did Niels Bohr observe that convinced him that every atom has a unique electron structure?
How light was refracted
How do orbitals in the quantum model of the atom differ from orbits in the planetary model?
There exact position can't be found
What is the most important use of an elements atomic number? What else an we know from a neutral atoms atomic number?
To tell elements apart. The number of electrons
How do atoms of the same element differ?
In the number of electrons
Explain the difference between an atoms mass number and atomic mass. Why are both needed in chemistry?
Mass number is the mass of the whole atom and atomic mass is the added mass of all the particles in the atom. Mass number and atomic mass can differ.
What arrangement of electrons is usually the most stable for an atom?
When there is 8 electrons in the outermost sphere.
(True or false) The element oxygen has eight valence electrons.
What makes an element radioactive? Which elements found in nature have mainly radioactive isotopes?
When the nuclei is unstable. Polonium though uranium.
What kinds of changes to a nucleus occur for each kind of nuclear decay?
For gamma decay there is no change except the nuclei loses energy. For alpha decay two protons and two neutrons are lost. For beta decay a beta particle is lost.
What is the source of energy released in fission and fusion reactions?