1. Atomic Structure Review

2. Who first proposed an atomic theory based on scientific knowledge?
John Dalton
Neils Bohr
Ernest Rutherford
JJ Thomson

3. Who first proposed a theory that describes how electrons exist in energy levels?
John Dalton
Neils Bohr
Ernest Rutherford
JJ Thomson

4. What happens when electrons absorb energy?
They go from lower energy levels to higher energy levels.
They go from higher energy levels to lower energy levels.
They produce unique atomic spectra.
They emit light.

5. What happens when electrons go from higher to lower energy levels?
They emit energy.
They produce unique atomic spectra.
They emit light.
All of the above

6. Who explained the behavior of positively charged particles being deflected from a metal foil as the nucleus?
Ernest Rutherford
John Dalton
James Chadwick
Niels Bohr

7. A nuclear particle that has about the same mass as a proton, but with no electrical charge, is called a(n)
nuclide.
neutron.
electron.
isotope.

8. What particle comprises about half the mass of an atom?
Positron
Neutron
Electron
None of the above

9. Isotopes are atoms of the same element that have different
principal chemical properties.
masses.
numbers of protons.
numbers of electrons.

10. An atom is electrically neutral because
neutrons balance the protons and electrons.
nuclear forces stabilize the charges.
the numbers of protons and electrons are equal.
the numbers of protons and neutrons are equal.

11. The smallest unit of an element that can exist either alone or in combination with other such particles of the same or different elements is the
electron.
proton.
neutron.
atom.

12. All isotopes of hydrogen contain
one neutron.
two electrons.
one proton.
two nuclei.

13. The atomic number of oxygen, 8, indicates that there are eight
protons in the nucleus of an oxygen atom.
oxygen nuclides.
neutrons outside the oxygen atom's nucleus.
energy levels in the oxygen atom's nucleus.

14. The total number of protons and neutrons in the nucleus of an atom is its
atomic number.
Avogadro number.
mass number.
average atomic mass.

15. As the mass number of an element’s isotopes of an element increases, the number of protons
decreases.
increases.
remains the same.
doubles each time the mass number increases.

16. All atoms of the same element have the same
atomic mass.
number of neutrons.
mass number.
atomic number.

17. The average atomic mass of an element
is the mass of the most abundant isotope.
may not equal the mass of any of its isotopes.
cannot be calculated.
always adds up to 100.

18. An aluminum isotope consists of 13 protons, 13 electrons, and 14 neutrons. Its mass number is
13.
14.
27.
40.

19. Carbon-14 (atomic number 6), the radioactive nuclide used in dating fossils, has
6 neutrons.
8 neutrons.
10 neutrons.
14 neutrons.

20. Neon-22 contains 12 neutrons. It also contains
12 protons.
22 protons.
22 electrons.
10 protons.

21. Which scientist described the existence of the neutron?
Chadwick
Thomson
Rutherford
Bohr

22. Which has a charge of +1?
proton
atom
electron
neutron

23. Which element has 14 protons?
Nitrogen
Silicon
Aluminum
Sulfur

24. According to the modern concept of the atom, which are located in the nucleus of an atom?
electrons and protons
protons only
neutrons and electrons
protons and neutrons

25. The nucleus of an atom is ____.
the central core and is composed of protons and neutrons
positively charged and has more protons than neutrons
negatively charged and has a high density
negatively charged and has a low density

26. What does the number 84 in the name krypton-84 represent?
the atomic number
the mass number
the sum of the protons and electrons
twice the number of protons

27. Using the periodic table, determine the number of neutrons in O.4 8 16 24

28. Which of the following statements is NOT true?
Atoms of the same element can have different masses.
Atoms of isotopes of an element have different numbers of protons.
The nucleus of an atom has a positive charge.
Atoms are mostly empty space.

29. How is the number of neutrons in the nucleus of an atom calculated?
Add the number of electrons and protons together.
Subtract the number of electrons from the number of protons.
Subtract the number of protons from the mass number.
Add the mass number to the number of electrons.

30. Which of the following statements is NOT true?
Protons have a positive charge.
Electrons are negatively charged and have a mass of 1 amu.
The nucleus of an atom is positively charged.
Neutrons are located in the nucleus of an atom.

31. The mass number of an element is the ____.
total number of subatomic particles in its nucleus
weighted average of the masses of the isotopes of the element
total mass of the isotopes of the element
average of the mass number and the atomic number for the element