Coursework

                                                   SCH4U

UNIT 1

ASSIGNMENT

PART A: K/U-10 MARKS

1. Explain why methane is not a polar molecule but ammonia is a polar molecule. Also draw the diagrams to explain.(3)

2. For each of the following elements, explain what type of bonds it will form and the reasons it forms this type of bond.include a brief outline of the steps involved:

Hydrogen, carbon , sodium and xenon.(3 marks – K/U)

3. What is the atomic symbol of the ion with:

(i) 15 protons, 15 neutrons, 15 electrons

(ii) 16 protons, 16 neutrons and 18 electrons  (1 marks – K/U)

4. Differentiate between the term “orbits and orbitals” (3 marks)

PART B : T/I- 10 MARKS :

Q5. For n=5 , what are the possible values of the quantum numbers .(  3 marks)

Q6. Which of the following set of orbitals are not allowed and why:  (2marks)

1. n= 3, l=3, m=0, s= -1/2
2. n=4, l=4,m=2,s=-1/2
3. n=4,l=1,m=1,s=1/2
4. n=2, l=1, m=-1, s=1

Q7. The second energy level in an atom can hold no more than 8 electron.Explain this limitation.(2 marks)

Q8. Write the electronic configuration of : (3 marks)

1. Mg²⁺
2. Si
3. Ca

PART C: A (10 MARKS)

Q9. Explain and name the bonding occurring in CaO with diagram. Elaborate the details. (3 marks)

Q10. Draw the lewis dot structure for : (3 MARKS)

1. ClO-

1. NO₂^–

1. C₂H₂

Q11. Use the VSEPR theory to predict the geometry of following substances .Also draw the structures: (4 marks)

1. BF3

1. NCl₃

1. H₂0

1. PCl₅

PART D: COMMUNICATION (10 MARKS)

Q12. Arrange in increasing order of electronegativity: (2 marks)

1. C, N, O
2. F,Cl,Br

Q13. Explain why covalent  bonds are formed (2 marks)

Q14. Draw and explain the hybridization in C_H4 and also mention the number of sigma and pi bonds, s and p-character.( 4 marks )

Q15. Explain hydrogen bonding with suitable example( 2 marks)