Press here to go back to the home page. press
2. The correct answer is "b". Protons are positively charged
particles with a mass of 1 amu. Each element consists of atoms with
a different number of protons (anywhere from 1-107). Example - Hydrogen
atoms contain one proton, Helium atoms contain two protons, and Lithium
atoms contain three proton. If a proton is taken from the nucleus of an
atom of one element, the atom will be transformed into an atom of
a different element. Example - If two protons are removed from an oxygen
atom, it will be transformed into carbon. This process on a
larger scale is called fission. If the two single hydrogen atoms
have their protons fused into a single nucleus, an atom of
helium will have been created. This process on a larger scale is
called fusion.
Press here to go back to the home page. press
3. The correct answer is "b". Electrons are negatively charged
with a mass of 0 amu. They are attracted to the positive charged nucleus
and will move around the nucleus in an orbital pattern instead of
being part of the nucleus.
Press here to go back to the home page. press
4. The correct answer is "b". The mass of a proton is .000000000000000000000000167
grams
-24
( 1 x 10 g) which is approximately one amu.
One amu is defined to be approximately the same weight as a proton.
Press here to go back to the home page. press
5. The correct answer is "c". Protons have the opposite charge
of an electron. These charges will be canceled by the negative
charges of electrons in a neutral atom.
Press here to go back to the home page. press
6. The correct answer is "a". Electrons are negatively charged. Electrons
repel other electrons and are attracted to the positively charged nucleus.
Electrons in the same orbit will repel one another. The attraction of an
electron to its positively charged nucleus forms an electron shell.
Press here to go back to the home page. press
7. The correct answer is "c". The mass of the neutron is approximately
the same as the proton. Its
-24
mass .000000000000000000000001660 grams (1 x 10 g) or 1
amu, slightly heavier than a proton.
Press here to go back to the home page. press
8. The correct answer is "a". The neutron does not have a charge. It
basically adds mass to the atom and does not effect any of the chemical
properties of its element.
Press here to go back to the home page. press
9. The correct answer is "c". The mass of the electron is .00000000000000000000000000911
grams
-28
( 9.1 x 10 g ) or 0 amu. This number is much smaller than the mass
of a proton (1 amu); therefore it is rounded off to 0.
Press here to go back to the home page. press
10. The correct answer is "c". Since neutrons do not have a charge
and protons have a positive charge the overall charge of the nucleus is
positive. If there are three protons in the nucleus than the charge
of the nucleus is positive three. If there are twenty
two protons in the nucleus of an atom than the charge of the nucleus
is twenty two.
Press here to go back to the home page. press
11. The correct answer is "b". It would take eight protons with a positive
one charge each to balance the eight negative charged electrons.
Press here to go back to the home page. press
12. The correct answer is "b". Since the original atom was neutral
and it lost two negatively charged electrons the over all charge of
the atom (ion) would be a positive two or +2.
Press here to go back to the home page. press
13. The correct answer is "d". Since the mass of electrons is negligible
compared to the mass of protons and neutrons, the total mass of an atom
is the combination of the mass (amu) of the neutrons and protons
in an atom.
Press here to go back to the home page. press
14. The correct answer is "a". Atomic number refers to the number
of protons in an atom.
Press here to go back to the home page. press
15. The correct answer is "a". If you were to add or take away
protons from an atom of an element, the chemical properties would
change. If you were to add or take away neutrons from an atom of an element
the chemical properties would remain the same; however, the mass of the
atom would change.
Press here to go back to the home page. press
16. The correct answer is "c". Neutrons would only add more mass to
the atom. For each neutron added, an additional weight of one amu would
be added.
Press here to go back to the home page. press
17. The correct answer is "a". Each naturally occurring element
contains several isotopes which may range from 3 to 12. The hydrogen element
is the only element which has different names for its isotopes. The other
elements are simply numbered.
Press here to go back to the home page. press
| Name of Isotope | Number of Protons | Number of Neutrons | Total Mass of Atom (amu) | Characteristics |
| hydrogen | 1 | 0 | 1 amu | most hydrogen on earth in this form |
| deuterium | 1 | 1 | 2 amu | twice as heavy as hydrogen |
| tritium | 1 | 2 | 3 amu | radioactive because unstable |
Press here to go back to the home page. press
19. The correct answer is "c". Fill the first shell first which can
hold a maximum of two electrons. Than place the remaining electrons in
the second shell until it is full. If there are still electrons left
after the second shell has been filled, place these in the third
shell.
Press here to go back to the home page. press
20. The correct answer is "b". The first shell would contain 2 electrons,
the second 8 electrons, and the third shell would contain the final 2
electrons. This outer shell is called the valence shell.
Press here to go back to the home page. press
21. The correct answer is "a". The first shell would contain
2 electrons, the second 8 electrons, and the third shell would contain
the final 7 electrons. This outer shell is called the valence shell.
Make sure this this definition is in your notes.
Press here to go back to the home page. press
22. The correct answer is "e". The first shell can only hold a maximum
of two electrons and the second, third, etc. when thery
are outer shells may have anywhere from one to eight.
Press here to go back to the home page. press
23. This formula represents a molecule consisting of one Mg atom and
two chlorine atoms.
Press here to go back to the home page. press
24. This molecular formula represents one molecule of glucose which
contains six atoms of carbon, twelve atoms of hydrogen and six atoms of
oxygen. Write a definition of molecular formula in your notes.
Press here to go back to the home page. press
25. The correct answer is 2 C12 H
22 O 11
The number two in front of the sucrose molecule represents two molecules of sucrose and the subscripts represents the number of atoms of each element in a single molecule.
Press here to go back to the home page. press