HW 04 ANS
REVIEW QUESTIONS
Chapter 4
- Complete each question below with an appropriate term:
a)Noble gases Un-reactive elements in the last group of the periodic table.
b)Alkaline-earth metals Elements in group 2 of the periodic table.
c)Transition metals Elements between the main group elements.
d)Halogens Elements in group 7 of the periodic table. - Name and write symbol for each element described below:
a) Alkali metal in period 4:K, potassium
b) Halogen in period 2:F, fluorine
c) Alkaline-earth metal in period 3:Mg, magnesium
d) Metalloid in period 3:Si, silicon
e) Noble gas in period 5:Xe, xenon - Complete each statement below with a suitable word or phrase:
A) The "soccer ball" model of the atom is attributed toJohn Dalton
B) Thomson discovered theelectron in 1897.
C) Rutherford discovered that the atom was mostly hollow through the
gold foil experiment.
D) The number of protons in an atom is called theatomic number
E) Isotopes of an atom have the sameatomic number but different
mass numbers
F) The group number of representative elements represents thenumber of valence electrons - For each element below, use the information given to determine the number of protons, neutrons and electrons in its atom, and write shorthand notation for each.
a) Krpton (Kr) atomic number (Z=36); mass number (A=84)
b) Barium (Ba) atomic number (
); mass number (
)
- Complete the missing information in the table below:
| Symbol | Ga |
|
| Protons |
|
15 |
| Neutrons | 39 |
|
| Electrons |
|
|
| Mass number |
|
31 |
- Complete the following table with the missing information:
| Ion | Number of Protons | Number of Electrons | Electrons Lost/Gained |
|
|
19 | 18 | 1 Lost |
|
|
12 | 10 | 2 lost |
|
|
8 | 10 | 2 gained |
|
|
13 | 10 | 3 lost |
- An unknown element
has the following isotopic data:
| Isotope | Mass (amu) | Abundance (%) |
| 1 | 80.0 | 60.0 |
| 2 | 84.0 | 30.0 |
| 3 | 82.0 | 10.0 |
Calculate the average atomic mass of this element.
Avg atomic mass
amu
8. What is the relationship between each pair of elements shown below:
a) One with 10 protons, 11 neutrons, 10 electrons and one with 11 protons, 10 neutrons and 11 electrons.
8. What is the relationship between each pair of elements shown below:
a) One with 10 protons, 11 neutrons, 10 electrons and one with 11 protons, 10 neutrons and 11 electrons.
These two elements are different elements (different atomic numbers) that have the same mass (same mass numbers).
b) One with 12 protons, 12 neutrons and 12 electrons and one with 12 protons, 14 neutrons and 12 electrons.
b) One with 12 protons, 12 neutrons and 12 electrons and one with 12 protons, 14 neutrons and 12 electrons.
These two elements are isotopes of each other, since they have the same atomic number but different mass numbers.