Chemistry 9th Objective Type
Time Allowed: 15 minutes Marks: 12
Note: You have four choices for each objective type question as A/B/C/ and D. The choice which you think is correct; fill that circle in front of that question number. Cutting or filling two or more circles will result in zero mark in that question.
Q.1: Which one of the following can be separated by physical means?
a) Mixture b) Element c) Compound d) Radical
2. The third abundant gas found in the earth crust is:
a) Carbon monoxide b) Oxygen c) Nitrogen d) Argon
3. Which one of the following molecule is not tri-atomic?
a) H2 b) O3 c) H2O d) CO2
4. Which one of the following is most penetrating?
a) Proton b) Electron c) Neutron d) Alpha particles
5. Which one of the following shell consists of three sub-shells?
a) O shell b) N shell c) L shell d) M shell
6. Who discovered the proton?
a) Goldstein b) J.J.Thomsan c) Neil Bohr d) Rutherford
7. Mendeleev periodic table was based upon the:
a) Electronic configuration b) Atomic mass
c) Atomic number d) Completion of a shell
8. Which one of the following halogen has the lowest electronegativity?
a) Fluorine b) Chlorine c) Bromine d) Iodine
9. Transition elements are:
a) All gases b) All metals c) All non-metals d) All metalloids
10. Atoms react with each other because:
a) They are attracted to each other b) They are short of electrons
c) They want to attain stability d) They want to disperse
11. Transfer of electrons between the two atoms results in:
a) Metallic bonding b) Ionic bonding
c) Covalent bonding d) Coordinate bonding
12. A bond pair in covalent molecules usually has:
a) One electron b) Two electrons c) Three electrons d) Four electrons
Essay type Marks:48 Time: 1:45 Hours
Section – I 2 X 15=30 Marks
2. Write short answers of any five parts from the following. 2×5=10
i. Define industrial chemistry
ii. State the reasons: soft drink is a mixture and water is a compound.
iii. What is the nature of charge on cathode rays?
iv. An element has an atomic number 17. How many electrons are present in K, L and M shells of the atom?
v. What type of covalent bond is formed in nitrogen molecule.
vi. Why shielding effect of electrons makes cation formation easy?
vii. Differentiate between lone pair and bond pair of electrons.
3. Write short answers of any five parts from the following. 2×5=10
i. Differentiate between homoatomic and heteroatomic molecules with examples.
ii. Define empirical formula with an example.
iii. A patient has goiter. How will it be detected?
iv. Give two properties of positive rays.
v. Why are noble gases not reactive?
vi. Metals are good conductor of electricity. Why?
vii. Ionic compounds are solids. Justify.
4. Write short answers of any five parts from the following. 2×5=10
i. Explain why are hydrogen and oxygen considered elements whereas water as a compound.
ii. Define atomic mass unit. Why is it needed?
iii. Write down the electronic configuration of Al3+ ion which have 10 electrons.
iv. Differentiate between shell and subshell with examples of each.
v. What do you mean by groups and periods in the Periodic Table?
vi. How is periodicity of properties dependent upon number of protons in an atom?
vii. Why HCl has dipole-dipole forces of attraction?
Note: Answer any two questions from the following.
- (i) List five characteristics by which compounds can be distinguished from mixtures.
(ii) Sulphuric acid is the king of chemicals. If you need 5 moles of sulphuric acid for reaction, how many grams of it will you weigh?
2. (i) What is an isotope? Describe the isotopes of hydrogen with diagrams.
(ii) What do you mean by electronic configuration? What are basic requirements while writing electronic configuration of an element (atom)?
3. (i) What is ionization energy? Describe its trend in the Periodic Table?
(ii) What is covalent bond? Explain the types of covalent bonds with at least one example of each type.