Chapter 4 Practice Test
What is the maximum number of electrons that an atomic orbital can contain
2
If an atom has 32 protons and 38 neutrons, what is its mass number
70
Which of the following provides the best analogy for an electron in an atomic orbital
A bee buzzing inside a closed jar
Which of the following most accurately represents John Dalton's model of the atom?
A tiny, solid sphere with an unpredictable mass for a given element
Which statement about electrons and atomic orbitals is NOT true
An electron has the same amount of energy in all orbitals
Which statement about subatomic particles is true
An electronic has far less mass than either a proton or neutron
The Greek philosopher Democritus coined what word for a tiny piece of matter that cannot be divided?
Atom
The number of protons in one atom of an element is that element's
Atomic number
In the nucleus of an atom, there are 15 protons and 16 neutrons. What is the atomic number and mass number of this isotope?
Atomic number = 15 Mass number = 31
To find the number of neutrons in an atom, you would subtract
Atomic number from mass number
Unlike Democritus, Aristotle did not believe that matter was composed of tiny, indivisible ________
Atoms
Which of the following is NOT part of John Dalton's atomic theory?
Atoms contain subatomic particles
John Dalton observed that elements always combine in the same ratio to form a particular ________
Compound
In an atomic model that includes a nucleus, positive charge is
Concentrated in the center of an atom
What did Rutherford conclude about the location of positive charge in an atom
Concentrated in the nucleus
J.J. Thomson's experiments provided evidence that an atom
Contains negatively charged particles
Which of the three subatomic particles-protons, electron, or neutron-- has the least mass?
Electron
Which subatomic particle has a negative charge
Electron
Which statement accurately represents the arrangement of electrons in Bohr's atomic model?
Electrons travel around the nucleus in fixed energy levels with energies that vary from level to level.
Who provided evidence for the existence of nucleus in an atom
Ernest Rutherford
An atom in which an electron has moved to a higher energy level is in a(an) ________ state
Excited
When all the electrons in an atom are in orbitals with the lowest possible energy, the atom is in its _______ state
Ground
Most calcium atoms have an atomic number of 20 and a mass number of 40, but some calcium atoms have a mass number of 38. What word could you use to describe these two kinds of calcium atoms
Isotope
How was Bohr's atomic model similar to Rutherford's model
It described a nucleus surrounded by a large volume of space
In Niels Bohr's model of the atom, electrons move
Like planets orbiting the sun
The _______________ of an isotope is the sum of the number of protons and neutrons in its nucleus
Mass number
The glowing of a neon light is caused by electrons emitting energy as they
Move from higher to lower energy levels
Protons and __________ are found in the nucleus of an atom
Neutrons
The nuclei of isotopes contain different numbers of __________
Neutrons
The diagram in Figure 4-1 shows the results of Rutherford's gold foil experiment. What caused some of the alpha particles to bounce straight back from the gold foil?
Nuclei in the gold atoms
If element Q has 11 protons, it's atomic _______ is 11
Number
The region in which an electron is most likely to be found in a (an) _________
Orbital
What do scientists use to predict the locations of electrons in atoms
Probability
Neutrons and __________ have almost the same mass
Protons
Which statement about subatomic particles is NOT true
Protons and neutrons have the same charge
What is the difference between an atom in the ground state and an atom in an excited state?
The atom in an excited state has more energy and is less stable than the atom in the ground state
Explain what the colors in a fireworks display reveal about the movement of electrons in atoms
The atoms go from a ground state to an excited state when the fireworks explode. Then the electrons return to a lower energy level and lose energy in the form of visible light
What can you assume has happened if an electron moves to a higher energy level?
The electron has gained energy
What does the electron cloud model describe
The most likely locations of electrons in atoms
Which of the following is unique for any given element
The number of protons
Suppose an atom had a mass number of 35. Which statement is true beyond any doubt?
The number of protons in the nucleus does not equal thr number of neutrons
Rutherford's gold foil experiment provided evidence for which of the following statements?
There is a dense, positively charged mass in the center of an atom
Which statement is true about oxygen-17 and oxygen-18?
They are isotopes of oxygen
A sample of calcium contains calcium-40, calcium-44, calcium-42, calcium-48, calcium-43, and calcium-46 atoms. Explain why these atoms can have different mass numbers but they must have the same atomic number.
They have different mass numbers because they have different numbers of neutrons. They have the same atomic number because they all have the same number of protons.
