Flashcards in C16 Terms Deck (45)
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1
law of definite proportions
Established that masses if chemical substances combine in definite repeatable ratios
2
core-envelope model
Based on the caloric theory
3
plum-pudding model
Atoms are masses that have a positively charged (pudding) in which the negatively charged electrons stay
4
nuclear model
Every atom has a nucleus and electrons circle around it
5
planetary model
Electrons circle around the nucleus
6
quantum model
Electrons move in waves around the nucleus
7
orbital
Subregions of space
8
nucleon
Neutrons and protons in the nucleus
9
elementary particle
Subatomic particles that are the building blocks of photons neutrons and electrons
10
atomic number (Z)
The number of protons in the nucleus
11
isotope
Aims of elements that have different numbers of neutrons
12
mass number
Tells isotopes apart
13
isotopic notation
Shows both the atomic and mass numbers of the element
14
atomic mass
The mass of an electron expressed in atomic mass units
15
atomic mass unit (u)
The mass equal to 1/12th the mad of a carbon atom
16
energy level
Represent the regions where an electron with a certain amount of energy is most likely to be found.
17
electron configuration
Is the arrangement of the energy levels and the positions that electrons can take within those energy levels for a given number of electrons.
18
valence electron
The electrons in the outermost energy level
19
nuclear chemistry
The study of changes in atomic nuclei
20
radioactivity
The emission of nuclear radiation
21
nuclear radiation
The rays and particles emitted by unstable nuclei
22
alpha particle
Positively charged particles
23
beta particle
Negatively charged particles
24
gamma decay
A nucleus shedding energy by releasing gamma rays
25
alpha decay
The atoms nucleus loses two protons and two neutrons
26
beta decay
The atom loses a beta particle and emits gamma rays
27
radioactive dating technique
Using nuclear decay to date things
28
nuclear bombardment reaction
When a nucleus is stuck by a high energy particle
29
nuclear fission
The splitting of an atom
30
chain reaction
When one atom after another is broken apart
31
nuclear fusion
The crushing of two atoms to form a larger atom
32
What is the most important aspect of a scientific model?
It has to work
33
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
34
What was the most significant question about the atom after Thomson's discovery of the electron?
The extra mass that was measured
35
What phenomenon did Niels Bohr observe that convinced him that every atom has a unique electron structure?
How light was refracted
36
How do orbitals in the quantum model of the atom differ from orbits in the planetary model?
There exact position can't be found
37
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
38
How do atoms of the same element differ?
In the number of electrons
39
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.
40
What arrangement of electrons is usually the most stable for an atom?
When there is 8 electrons in the outermost sphere.
41
(True or false) The element oxygen has eight valence electrons.
True
42
What makes an element radioactive? Which elements found in nature have mainly radioactive isotopes?
When the nuclei is unstable. Polonium though uranium.
43
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.
44
What is the source of energy released in fission and fusion reactions?
The nucleus.
45
