Download Chemistry 1/2 Questions 14.3 Atomic size The size of an atom is

Chemistry 1/2
Questions 14.3
Atomic size
The size of an atom is measured with an atomic radius in angstroms (10-8 meters). The graph below
shows the atomic size for the elements lithium through argon.
Element
2
Atomic Radius
1
0
Li
1.
Be
B
C
N
O
F
Ne Na Mg Al
Si
P
S
Cl
Ar
Are the elements increasing or decreasing in size as you go across a period of the periodic table?
The size variation can be explained by the idea of charge density
charge density =
2.
Li
the number of + or – charges
volume the charges occupy
List the number of electrons, protons, and neutrons in lithium and beryllium
Be
What particles are added to increase atomic number?
3.
Which has a larger volume, an electron orbital or the nucleus of an atom?
4.
Which will have a higher charge density, the electrons in a suborbital or the protons in the nucleus?
Why?
5.
What effect does increasing the charge density of the nucleus have on the atomic size?
6.
Why would nonmetals have a higher attraction for electrons than metals?
The graph below shows the atomic radius of elements in the 1A group
Element
4
Atomic radius
3
2
1
0
H
Li
Na
K
Rb
Cs
7.
Does the size of the atom generally increase or decrease as you go down a periodic table group?
8.
How does the number of filled energy levels effect the atomic size?
Chemistry 1/2
Ionization energy
Ionization energy is the energy needed to remove the outermost electron from an atom. The energy needed to
remove an electron is measured with a voltmeter. The graph below shows the energy needed to remove each
electron from carbon.
Ionization energies for Carbon
50000
Energy used
40000
30000
20000
10000
0
2p2
2p1
2s2
2s1
1s2
1s1
1.
What kind of ion is formed when an electron is removed from carbon?
2.
Why does it become more difficult to remove the 2 nd, 3rd and 4th electrons?
3.
Why is it so much harder to remove the 1s2 electron than the 2s1 electron?
The graph for ionization energies of Li through Ar would look like this
Element
30
Ionization Energy
20
10
0
Li
Be B
C
N
O
F
Ne Na Mg Al
Si
P
S
Cl Ar
4.
Does the ionization energy increase or decrease across a period of the periodic table?
5.
Be
Write the electron configurations for Be and B
B
Why is it easier to remove the outer electron from boron than beryllium?
6.
N
Write the electron configurations for nitrogen and oxygen
O
Why is it easier to remove an electron from oxygen than nitrogen?
7.
Ne
Write the electron configurations for Ne and Na.
Na
Why is it easier to remove an electron from sodium than neon?
Ionization energy trends down a group from C to Pb look like this
Element
12
Ionization energy
11
10
9
8
7
C
8.
Si
Ge
Sn
Pb
Does the attraction for the outer electrons increase or decrease as the atomic size increases?
9.
What’s the shielding effect? Why do filled d and f orbitals decrease attraction for outer electrons more
than filled s or p orbitals?
The graph below shows the size of the atoms and ions of the 5A group
Element name
0.24
Size of atom
0.22
Size of ion
0.2
0.18
0.16
0.14
0.12
0.1
0.08
0.06
N
10.
N
P
As
Sb
Bi
Write the electron configurations for nitrogen and phosphorus
P
What ionic charge will ions formed from nitrogen and phosphorus have?
11.
Why do atoms become larger when they gain extra electrons to ionize?
12.
Sb
Write the electron configurations for antimony and bismuth.
Bi
Why are antimony and bismuth more willing to lose electrons than gain them?
Why do atoms become smaller when they give up electrons to ionize?
What electrons are lost to form the +3 and +5 charges?