chapter 6: periodic table Flashcards
How is the periodic table organized?
By properties
Who was Dmitri Mendeleev?
A Russian chemist and teacher
Why is Dmitri Mendeleev important?
Made the first periodic table
How did Dmitri Mendeleev arrange the periodic table?
- Arranged elements in order of increasing atomic mass
- He left blanks for yet undiscovered elements
What did Henry Moseley do in 1913?
Arranged elements according to increasing atomic number on periodic table
Who’s table is used today, Mendeleev or Moseley?
Moseley
What is a group or family?
Vertical (down) rows on periodic table
What is a period?
Horizontal rows on periodic table
How many periods are on the periodic table?
7
How many groups/families are on the periodic table?
18
Reactivity increases/decreases as you go up/down?
increases as you go down
1st group
alkaline metals
2nd group
alkaline earth metals
3rd-12th group
transition metals
13th group
boron
14th group
carbon
15th group
nitrogen
16th group
oxygen or chalcogens
17th group
halogens
18th group
noble gasses
F block
inner transition metals
What is the periodic law?
When elements are arranged in order of increasing atomic number, there is a periodic repetition of their physical and chemical properties.
Where are metals on the periodic table?
to the left (everything under metalloids)
Where are non-metals on the periodic table?
Hydrogen and everything up from metalloids
Where are metalloids on the periodic table
B, Si, Ge, As, Sb, Te, Po
Metals are…
electrical conductors, have luster, ductile, malleable
Non-metals are…
generally brittle and non-lustrous, poor conductors of heat and electricity
Metalloids are…
Properties are intermediate between metals and nonmetals
Alkaline metals are…
Extremely reactive
What is Atomic Radius/Size?
increases down the group and decreases from left to right across the period
What is Ionization Energy?
energy needed to remove an electron
Exceptions with IE
drops between 2nd-13th group and 15th-16th group
Drop between Be and B
- Be is fully filled in s block meaning its stable and less likely to give an electron
- B is less than half filled; ⅙ of p block so its unstable
Which atoms have the highest and lowest IE?
- H has the highest
- Fr has the lowest
What is Electronegativity?
force of attraction of one atom to another atoms electrons
What is Electronafinity?
the amount of energy released when an atom accepts and electron
What group has the highest electronafinity?
Halogens
Nuclear charge =???
number of protons - number of inner electrons
Why does IE decrease?
Radius and shielding increases
Which group tends to form 1+ ions?
Alkali metals
Which group tends to form 2+ ions?
Alkali earth metals
Which group tends not to form ions or react?
Noble gases
How does the periodic table account for the pattern of IE?
Atoms have more protons and more pull on electrons across a period and more shells or energy levels and weaker pull on electrons down a group.
The size of an element’s atomic radius __________ from left to right across the periodic table.
Decreases
The halogens tend to form anions because….
They are each only one electron away from having a full outer shell
Name the only element touching the stair-step line that is NOT a metalloid
Aluminum
When a metal atom becomes a cation…
Its ionic radius is smaller than its atomic radius
Mendeleev left spaces in his periodic table and predicted several elements and their…
Properties
Mendeleev noticed that properties of elements usually repeated at regular intervals when the elements were arranged in order of increasing
Atomic mass
Moseley’s work led to the realization that elements with similar properties occurred at regular intervals when the elements were arranged in order of increasing
atomic number
Who used his experimental evidence to determine the order of the elements according to atomic number?
Moseley
The most useful source of general information about the elements for anyone associated with chemistry is a…
Periodic table
The periodic table…
Permits the properties of an element to be predicted before the element is discovered.
Evidence gathered since Mendeleev's time indicates that a better arrangement than atomic mass for elements in the periodic table is an arrangement by
Atomic number
What are the radioactive elements with atomic numbers from 90 to 103 in the periodic table called?
actinides
Argon, krypton, and xenon are
Noble gasses
Which two periods have the same number of elements?
4 and 5
The discovery of the noble gases changed Mendeleev’s periodic table by adding a new
group
The periodic law states that the physical and chemical properties of elements are periodic functions of their atomic
Numbers
Elements in a group or column in the periodic table can be expected to have similar
properties
For groups 1, 2, and 18, the atomic number of the fourth element in the group is ____ more than the preceding element.
18
Krypton, atomic number 36, is the fourth element in Group 18. What is the atomic number of xenon, the fifth element in Group 18?
54
Identify the sublevels in a period that contains 32 elements.
s, p, d, f
How many elements are in a period in which only the s and p sublevels are filled?
Period 6
The length of each period in the periodic table is determined by the
sublevels being filled with electrons.
In Period 3 there are 8 elements. What sublevel(s) is (are) being filled?
s and p
Period 4 contains 18 elements. How many of these elements have electrons in the d sublevel?
16
The period of an element can be determined from its
electron configuration
Elements to the right side of the periodic table (p-block elements) have properties most associated with
nonmetals
Elements in which the d-sublevel is being filled have the properties of
Metals
The elements that border the zigzag line in the periodic table are
metalloids
The group of 14 elements in the sixth period that have occupied 4f orbitals is the
Lanthanides
For Groups 13 through 18, the total number of electrons in the highest occupied level equals the group number
minus 10
Periods with occupied f sublevels
are not assigned group numbers
In nature, the alkali metals occur as
compounds
atomic radius
increases as you go down; and decreases as you go left to right
IE
decreases as you go down; increases as you go right
Electronafinity
decreases as you go down; increases as you go right
electronegativity
decreases as you go down; increases as you go right
positive ion
cations
negative ion
anions