HUMAN NERVOUS AND GLANDULAR SYSTEM

HUMAN NERVOUS AND GLANDULAR SYSTEM.
1. Name three membrane that completely cover the brain.
- The three membrane that completely covers the brain are:
 Duramater, Piamater, Arachnoid.

2. Where is cerebrospinal fluid found? Write it's one function.
- Cerebrospinal fluid is found between piamater and Arachnoid. It's function is to protect the brain and spinal cord from the external jerks and shocks.

3. Where is spinal cord found? Write it's major functions.
- Spinal cord is found inside the vertebral column. It's function are as follows:
a. It controls and co-ordinates the reflex action.
b. It connects a large part of  the peripheral nervous system to the brain.

4. Draw a well labeled diagram of neuron and show the axon and dendrites.

INVERTEBRATES

1. Which types of silkworms do we cultivate in Nepal?
- The types of silkworm that we cultivate in Nepal are:
a. Seri silkworm (Bombyx mori)- It feeds upon Mulberry leaves.
b. Eri sikworm (Attacus ricini)- It feeds upon castor leaves. 

2. What is cocoon?
- A cocoon is the silky envelope rolled by the larvae of many insects such as silkworm.

3. What is the length of cocoon that can be extracted from a single cocoon?
-  The length of silk thread that can be extracted from a single cocoon is 1000 feet long.

4. In which stage of life cycle of silkworm, the silk is produced?
- Silk is produced in the cocoon stage of the life cycle of silk worm.

MATERIALS USED IN DAILY LIFE

1. What is cement? Write it's materials.
- Cement is a mixture of calcium aluminate and calcium silicate, which becomes hard and strong when mixed with water and left for some time.
It's raw materials are:
a. Lime stone (CaCO3)
b. Special type of clay (AL2O3. SiO2).

2. Why is gypsum added in cement and lead monoxide in the ordinary glass?
- Gypsum is added in the cement because it increases the quality and setting time of the cement.
- Lead monoxide is added in the ordinary glass because it reduces the temperature of molten material to increase work time with glass.

3. Define cement slurry and cement clinker.
- Cement slurry is defined as the powder mixture of calcium carbonate and clay mixed with water.
- Cement clinker is defined as the reddish colored substance obtained after heating cement slurry at 1600ºC.

4. Write the full form of RCC.
- The full form of RCC is Reinforced Concrete.

5. Write the composition of ordinary glass.
- The composition of ordinary glass are as follows:
a. Silica (50%)
b. Broken glass (25%)
c. Sodium carbonate (15%)
d. calcium carbonate (10%).

6. Which chemical is used to make red, black and blue colored glass?
- The chemicals used to make red and blue colored glass are Copper oxide, Nickel oxide and cobalt oxide respectively.

HYDROCRBON AND IT'S COMPOUNDS

1. Write the full form of IUPAC.
- The full form of IUPAC is International Union of Pure Applied Chemistry.

2. write about saturated and unsaturated hydrocarbons.
- Hydrocarbon with a single covalent bond between the carbon atoms are called saturated hydrocarbons. They are also called alkanes and paraffin which are less reactive towards chemical reaction. For eg. Methane (CH4), ethane (C2H6) etc.

- Hydrocarbons with double or triple covalent bond between carbon atoms are called unsaturated hydrocarbons. They are of two types alkenes (having double bond between carbons) and alkynes (having triple bond between carbons).
Eg. of alkene- Ethene (C2H4), propene (C3H6) etc.
Eg. of alkyne- Ethyne (C2H2), propene (C3H4) etc.

3. Write the structural formula of butane, propane and acetylene.

 

              BUTANE

                PROPANE

                                                                    

          ACETYLENE (ETHYNE)

METALS

1. Write two ores of iron.
- The two ores of iron are Hematite (Fe2O3) and Magnetite (Fe3O4).

2. Write any two physical properties of iron.
- The two physical properties of iron are:
a. Its specific gravity is 7.86.
b. It's M.P is  about 1500ºC and B.P is about 2500ºC.

3. What is atomic weight of iron? Define rusting.
- The atomic weight of iron is 56. Rusting is defined as the process of formation of hydrated iron oxide when iron comes in contact with moist air.
  4Fe +3O2 + 3H20-------- 2Fe2O3.3H2O

4. Write two uses of iron.
- The two uses of iron are:
a. It is used in construction of buildings, bridges etc.
b. It is used in manufacture of steels.

5. Write two ores of Aluminium and its atomic weight.
 - The two ores of aluminium are Bauxite ( Al2O3.2H20) and Felspar ( KAlSi3.O8). It's atomic weight is 27.

6. Write any two uses of Aluminium.
- The two uses of Aluminium are:
a. It is used to wrap food materials.
b. It is used to make parts of aeroplanes and light equipment.

7. Write two properties of Al.
- The two properties of Al are as follows:
a. It's specific gravity is 2.7.
b. It's M.P is 660ºC and 1800ºC.

8. Why is aluminium used to make aeroplanes?
- Aluminium is used to make aeroplanes because it is lighter metal and doesn't corrodes as easily as iron.

9. Name any two ores of copper.
- The two ores of copper are  Chalcopyrite (CuFeS2) and Chalcocite (Cu2S).

10. Why is copper used to make electric wires?
- Copper is used to make electric wires because it is good conductor of electricity.

11. Write two uses and properties of copper.
-  The two uses of copper are:
a. It is used to make electric wires.
b. It is used to make alloys, coins and utensils.
- The two properties of copper are:
a. It's specific gravity is 8.95.
b. It's M.P is 1083ºC and 2350ºC.

12. Write two ores of silver with atomic weight.
- The two ores of iron are Argentite (Ag2S) and Horn silver (AgCl). It's atomic weight is 107.88.

13. Write two properties and uses of silver.
 - The two properties of silver are:
a. It's specific gravity is 10.5.
b. It's M.P is 960ºC and 1955ºC.
- The two uses of silver are:
a. It is used in electroplating and making coins.
b. Silver bromide is used in photography.

SOME GASES

CARBONDIOXIDE
1. What are the main sources of carbondioxide?
- Rhe main sources of carbondioxide are plants and animals, limestone (CaCO3), magnetite (MgCO3) etc.

2. How is CO2 prepared in lab?
- In the laboratory CO2 is prepared by the reaction of calciun carbonate with dilute hydrochloric acid.
CaCO3 + 2HCl----CaCl2 +H2O  + CO2

3. How is CO2 gas collected?
- Since CO2 is heavier than air because it is heavier than air.

4. How is CO2 gas tested?
- CO2 gas can be tested by following ways:
i. By inserting a burning match stick inside the gas jar. If it extinguished, CO2 will be present.
ii. When a burning magnesiun ribbon keeps burning even after inserting it inside the gas jar, it means CO2 is present.
iii. Blue litmus paper turns into red.

5. How is CO2 prepared in large quantity in industries?
- CO2 and lime are obtained when limestone is heated at very high temperature.
CaCO3   --------  CaO+ CO2

ACID, BASE AND SALT

1. Define acid and base with example.
- An acid is a compound which gives hydrogen ion (H+) wheh dissolved in water. For example, HCl, H2SO4 etc.
- A base is a compound which gives hydroxyl ion when dissolved in water. For example, NaOH, KOH etc.

2. What are the types of acid?
- On the basis of sources acid are divided into two types:
a. Organic acid- The acids found in the body of living organisms is known as organic acid. For example, tartaric acid, citric acid etc.
b. Inorganic acid (Mineral acid)- Acids prepared in the laboratory is called inorganic acids. For example, HCl, HNO3 etc.