Ions and Ion Formation
A negatively charged ion is called a ______.
anion
How many electrons can the second energy level (n = 2) shell hold?
8e-
Which group has 7 valence electrons?
Group 17
Each orbital can hold a maximum of ___ electrons.
2
Which element has the electron configuration 1s22s22p1?
boron (B)
Which group is most likely to form 2+ cations?
Group 2
Elements in the same period have the same number of ______.
shells
Draw the Lewis Diagram for a calcium (Ca) atom.
2 valence e- (group 2)
How many orbitals are in a d subshell?
5
When an electron jumps from the n = 1 to the n = 3 energy level, what must occur?
a) The atom releases energy
b) The electron absorbs a photon with the exact energy difference
c) The atom becomes ionized
d) The electron’s mass increases
b) The electron absorbs a photon with the exact energy difference
Possible confusion: option C is incorrect because the electron is not leaving the atom, only moving to a higher energy level inside the atom.
What charge does a selenium (Se) ion have?
2-
Electrons in the third shell (n = 3) have more / less energy than those in the second shell (n = 2).
more
Draw the Lewis Diagram for a bromine (Br) atom.
7 valence e- (group 17)
How many electrons can a 4f subshell hold?
14e-
Write the electron configuration for fluorine (F).
1s22s22p5
An atom has 16 protons, 18 electrons, and 16 neutrons. Identify the element and write its ion symbol and charge.
16 protons → Sulfur (S)
net charge = 16p+ - 18e- = -2
Final ion: S2-
Remember neutrons do NOT affect the charge
Draw a Bohr model of an argon (Ar) atom.
Period 3 indicates 3 shells
1st shell has 2e-
2nd shell has 8e-
3rd shell has 8e-
Total electrons: 18e- (atomic number 18)
Valence electrons: 8e- (group 18)
Why are Group 18 elements stable and unreactive?
Elements in this group have a full outer shell and fulfill the octet rule (8e-).
Which subshells are present in the 2nd shell (n = 2)?
s and p
An electron in a hydrogen atom transitions from the n = 4 level to the n = 2 level. Which of the following is true?
a) The electron absorbs energy and a photon is emitted.
b) The electron releases energy and a photon is emitted.
c) The electron releases energy and a photon is absorbed.
d) The electron absorbs energy and no photon is emitted.
b) The electron releases energy and a photon is emitted.
Write the correct ionization equation for beryllium (Be).
Be → Be2+ + 2e-
Draw a Bohr model of a potassium (K) atom and label the shells.
Period 4 indicates 4 shells
n = 1 shell has 2e-
n = 2 shell has 8e-
n = 3 shell has 8e-
n = 4 shell has 1e-
Total electrons: 19e- (atomic number 19)
Valence electrons: 1e- (group 1)
Draw the Lewis Diagram for an oxide ion.
8 valence e-
charge: 2-
What is the maximum number of electrons the 5th shell (n = 5) can hold?
50e-
max electrons = 2n2
2(52) = 2(25) = 50
Which factor determines the color (wavelength) of light emitted in an atomic emission spectrum?
a) Number of protons in the atom
b) Energy difference between the two levels involved in the transition
c) Number of valence electrons in the atom
d) The mass of the electron
b) Energy difference between the two levels involved in the transition