Chapter 14 Unit Test
The charge on a proton is
+1e
The letter e represents the elementary charge. In normal matter, the charge that would not be found is:
+2.5e
The mass of an electron is about:
1800 times lighter than a proton
An atom contains 11 electrons. If a 12th electron were added to the atom, the energy level into which it would be placed is energy level:
3
The diagrams below, in which arrows indicate the direction of movement, represent charged particles placed near one another. The diagram that correctly represents the motion of the charged particles is:
3
A common isotope of Carbon has an atomic number of 6 and a mass number of 13. How many neutrons are in an atom of this isotope?
7
A common isotope of iron (Fe) has an atomic number of 26 and a mass number of 56. The total number of subatomic particles in the nucleus is:
82
Which of the reactions shown in Figure 14-1A illustrates beta decay?
A
Which of the following is a TRUE statement about atoms?
all atoms of the same element have the same number of electrons and protons, but may have different numbers of protons
Of the following statements, the one which is ALWAYS TRUE is:
all lithium atoms contain the same number of protons
In Rutherford's gold foil experiment, he bombarded gold foil with helium ions. Which type of radioactivity shown in Figure 14-1A was responsible for creating the helium ions?
alpha decay
The "building blocks" of matter are:
atoms and molecules
Fireworks contain different elements in them for displaying different colors. The different colors occur because:
atoms of various elements emit light at different frequencies
The diagram below represents the electron energy levels for the first two levels of an atom. The dark circles show a filled electron energy level.The diagram that would best represent an atom whose nucleus contains 5 protons and 4 neutrons is:
c
What is the fundamental property of matter that can either be positive or negative?
charge
Electrons are bound to the nucleus by:
electromagnetic force
A charged particle that accounts for nearly half the mass of an atom is the:
electron
A particle with zero charge found in the nucleus of an atom is called a(n):
electron
British physicist J. J. Thomson was the first to identify the
electron
An atom contains ____ in various energy levels
electrons
Electrons with higher energy are located:
farther from the nucleus of the atom
Which type of radioactivity in Figure 14-1A leaves the atomic number unchanged?
gamma decay
Atoms with the same atomic number but different atomic mass are called:
isotopes
Atoms with the same atomic number but different atomic mass are called:
istopes
According to Figure 14-1A, which of the following statements is true of gamma radiation?
it is a form of pure energy
The diagram below represents a spectrum. Each line is a different color of light. The bright colored lines represent:
light of different energies from an element
The mass of an atom is determined mainly by the:
mass of the neutrons and protons
atom emits light when one of its electrons:
move from a high energy level to a low energy level
An atom absorbs energy as its electrons
move from a low energy level to a high energy level
Compared to protons, electrons have:
much smaller mass and opposite charge
Many models have been developed to explain the nature of atoms. The model that helped scientists to understand energy levels of atoms was developed by
niels bohr
Protons and neutrons are found grouped together in the:
nucleus
What do we call the tiny core at the center of an atom, containing most of the atom's mass and all of its positive charge?
nucleus
The ____ is one kind of particle that makes up the atom and carries a positive charge
proton
Why don't all the electrons in an atom fall to the lowest energy level?
the lowest energy level can only hold 2 electrons
When Ernest Rutherford directed helium ions at gold foil, some of the helium ions bounced back in the direction they came from, rather than passing through. What was the his explanation of this unexpected result?
the mass of the gold atom is concentrated in a tiny, dense core
Atomic number is:
the number of protons in an atom
Which of the following statements about two isotopes of the same element is FALSE?
the number of protons might be different between the two isotopes
Atoms of the same element may contain
the numbers of neutrons but a different number of protons
Protons and neutrons in the nucleus are held together by:
the strong nuclear force
A group of students use a spectroscope to analyze three light sources. Different bright, vertical lines appear on the as the light from each source enters the spectroscope. Each light source shows a different spectral pattern because:
there are different elements associated withe these light sources
When an unstable isotope undergoes alpha decay, it gives off
two protons and two neutrons
Do any of the atom diagrams below represent atoms of the same element?
yes atom A and atom C are the same element
The charge on a complete atom is equal to:
zero
