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25 Cards in this Set

  • Front
  • Back
When Rutherford had a stream of alpha particles hit a gold foil, most of the particles
went almost straight through
X-rays are similar to
gamma rays
Which radiation has no electric charge associated with it?
gamma rays
Both X-rays and gamma rays are emitted from
different parts of the atom
The sources of Xrays and gamma rays, respectively, are
electron clouds and the atomic nucleus
A nucleon is either
a proton or a neutron
Once an alpha partile is outside the nucleus it is
electrostatically repelled
An atom with an imbalance of electrons to protons is
an ion
Deuterium and tritium are both
forms of hydrogen
isotopes of the same element
both of these
The atomic number of an element is the same as the number of its
Different isotopes of an element have different numbers of
Most alpha particles fired at a gold foil passthrough undeflected because the
atoms of gold, like any other atoms, are mostly empty space
Generally speaking, the larger a nucleus is, the greater its
The half life of an isotope is one day. At the end of three days, how much of the isotope remains?
one eight
According to Niels Bohr, an electron in an excited state could give off
several photons in a series of transitions to the ground state
The Bohr model of the atom is similar to
miniature solar system
We now consider the Bohr model of the atom to be
defective and oversimplified but still useful
Compared to the average diameter of a hydrogen atom, the average diameter of a helium atom is
Heavy atoms are not appreciably larger in size than light atoms because the nuclei of heavy atoms have more
electric charge
What is it that electrons have that protons always have in equal magnitude?
X-rays may be regarded as
high frequency radio waves
In the Heliocentric World System
the Sun is at the center of the universe and planets revolve around it.
According to Newton, gravitation is
a universal attractive force.
According to the Big Bang Model,
the universe is expanding.
Dark Energy is thought to be
the cause of the acceleration of the universe.