Question

part c: electron configuration

1. how many electrons can each level hold? 1st = __ 2nd = 3rd = __
2. what term is used for the electrons in the outermost shell or energy level? ____
3. scientists use two types of diagrams to show the electron - configuration for atoms. follow your teacher’s directions to complete the diagrams.

sulfur
atomic # = 16
atomic mass = 32
protons = ____
neutrons = ____
electron = ____
bohr diagram
shows all electrons
lewis structure
shows valence electrons
s

1. calculate the missing information and then draw the bohr diagram and lewis structure for each element.

li
atomic # = 3
mass # = 7

of p = ____

of n = ____

of e = ____

ne
atomic # = 10
mass # = 20

of p = ____

of n = ____

of e = ____

mg
atomic # = 12
mass # = 24

of p = ____

of n = ____

of e = ____

cl
atomic # = 17
mass # = 35

of p = ____

of n = ____

of e = ____

he
atomic # = 2
mass # = 4

of p = ____

of n = ____

of e = ____

si
atomic # = 14
mass # = 28

of p = ____

of n = ____

of e = ____

(1) which elements had a filled outermost shell? ____
(2) which element would be most likely to lose electrons in a chemical bond? ____
(3) which element would be most likely to gain electrons in a chemical bond? ____
(4) which elements are not likely to bond with other elements? ____ why?

Explanation:

Step1: Recall atomic number properties

The number of protons (P) is equal to the atomic number. The number of electrons (E) is equal to the number of protons in a neutral atom. The number of neutrons (N) = Mass number - Atomic number.

Step2: For Sulfur (S)

Atomic number = 16. So, Protons = 16, Electrons = 16. Mass number = 32, Neutrons = 32 - 16=16.

Step3: For Lithium (Li)

Atomic number = 3. Protons = 3, Electrons = 3. Mass number = 7, Neutrons = 7 - 3 = 4.

Step4: For Neon (Ne)

Atomic number = 10. Protons = 10, Electrons = 10. Mass number = 20, Neutrons = 20 - 10 = 10.

Step5: For Magnesium (Mg)

Atomic number = 12. Protons = 12, Electrons = 12. Mass number = 24, Neutrons = 24 - 12 = 12.

Step6: For Chlorine (Cl)

Atomic number = 17. Protons = 17, Electrons = 17. Mass number = 35, Neutrons = 35 - 17 = 18.

Step7: For Helium (He)

Atomic number = 2. Protons = 2, Electrons = 2. Mass number = 4, Neutrons = 4 - 2 = 2.

Step8: For Silicon (Si)

Atomic number = 14. Protons = 14, Electrons = 14. Mass number = 28, Neutrons = 28 - 14 = 14.

Step9: Answer questions about bonding

(1) Elements with filled outermost shell: Ne, He. They have a stable electron - configuration (2 for He and 8 for Ne in the outermost shell).
(2) Element most likely to lose electrons: Li. It has 1 valence electron and wants to achieve a stable configuration by losing it.
(3) Element most likely to gain electrons: Cl. It has 7 valence electrons and wants to gain 1 electron to have a stable octet.
(4) Elements not likely to bond: Ne, He. They have a full outermost shell and are chemically stable.

Answer:

For Sulfur: Protons = 16, Neutrons = 16, Electrons = 16.
For Lithium: Protons = 3, Neutrons = 4, Electrons = 3.
For Neon: Protons = 10, Neutrons = 10, Electrons = 10.
For Magnesium: Protons = 12, Neutrons = 12, Electrons = 12.
For Chlorine: Protons = 17, Neutrons = 18, Electrons = 17.
For Helium: Protons = 2, Neutrons = 2, Electrons = 2.
For Silicon: Protons = 14, Neutrons = 14, Electrons = 14.
(1) Ne, He
(2) Li
(3) Cl
(4) Ne, He; They have a full outermost shell and are chemically stable.