Bece Bece science mock episode 8 questions and answers
Bece science mock episode 8. Section A
1.a. the diagram below is an illustration of an electric circuit. Study the diagram carefully and answer the questions that follow
I. Identify the components labeled from I to VI
II. State the functions of the parts labeled from I to VI.
III. What will be observed when the circuit is closed?
b. The diagrams below are illustrations of the first flour elements on the periodic table. Study them carefully and answer the questions that follow
I. Identify the elements with electronic structure I to IV.
II. Give the symbols of each of the elements labeled from I to VI
III. Write down the electronic configuration of each of the elements from I to IV.
IV. Group the elements under metals and nonmetals.
c. The diagram below is an illustration of a natural cycle that occurs in the environment. Study the set carefully and answer the questions that follow
I. Identify the natural cycle illustrated in the diagram above
II. Name the processes labeled from I to IV
III. Explain each of the processes labeled from I to IV
IV. Identify two human activities that disrupt the cycle above.
d. The diagram below is an illustration of a weather instrument. Study it carefully and answer the questions that follow
I. Identify the instrument above and state its use.
II. In what units is the instrument calibrated?
III. State two positive ways in which the element of weather measured with the instrument affects agriculture.
IV. State two negative Ways in which the element of weather measured with the instrument affects agriculture
Bece Science mock episode 8 questions and answers
Solution
1. a. i. Identification of electrical components
I- cell/ battery
II- key or switch
III- ammeter
IV- lamp or bulb.
V- variable resistor or rheostat
VI- voltmeter
Ii. functions of the components
I- cell: it supplies electrical energy
II- key or switch: it used to open and close the circuit
III- ammeter: it is used for measuring electric current.
IV-lamp or bulb: it converts electrical energy to light energy
V- variable resistor or rheostat: it is used to change the resistance in an electric circuit
VI- voltmeter: it is used to measure potential difference
III. Observation when the circuit is closed
The bulb will light or the ammeter will deflect or the voltmeter will deflect.
b. I- hydrogen
II- helium
III- lithium
IV- beryllium
II) symbols of elements
Hydrogen- H.
Helium- He.
Lithium- Li.
Beryllium- Be
III. Electronic configuration of elements
Hydrogen (1)
Helium (2)
Lithium (2, 1)
Beryllium (2, 2)
IV) grouping of elements as metals and nonmetals
Metals. Non metals
Hydrogen. Helium
Lithium
Beryllium
c. I. Identification of the natural cycle
The carbon cycle
Ii) naming of labeled processes
I- photosynthesis
II- combustion
III- respiration
IV- decay or decomposition
III) explanation of processes
Photosynthesis
It is the process where green plants manufacture their own food using carbon dioxide, glucose and sunlight
Combustion
It is the rapid chemical reaction between a fuel and oxygen resulting in the production of heat and energy
Respiration
It is the breaking down of food to release energy with or without the use of oxygen
Decomposition
It is the process where dead organic substances are broken down into simple forms
IV) human activities that disrupt the carbon cycle
– bush burning
– deforestation
– burning of fossil fuel
– afforestation
d. Identification of instructions
Rainguage: it is used to measure amount of rain full over a period of
Ii. The unit the instrument is calibrated
Millimeters or litres per square meter
III) position ways weather element ( rainfall) affects agriculture
– provides water to support plants growth
– it helps in seeds and fruits dispersal
– it helps in irrigation
– it helps in pollination
IV) negative Ways weather element ( rainfall) affects agriculture
– it leads to the distribution of pests and diseases
– can cause flooding and soil erosion
– it can lead to leaching of soil nutrients
– can cause certain crops to rot .
Bece science mock episode 8 questions and answers
2. ai. Draw the electronic configuration for nitrogen atom
Ii. Why is it that, water in a clay pot is still cool during hot weather
b. Describe how electricity is generated from the wind.
c. Name three factors that determine the weather of an area.
d. Explain why carbon is important to life on earth
3.a. I. State two characteristics of the wet season
Ii. State two characteristics of the dry season
b. State the use of the following instructions
I. Barometer
Ii. Wind vane
III. Hygrometer
c. Give three effects of illegal electric connections in the home
d. List the first ten elements on the periodic table and give their symbols.
4. a.i. explain how the submarine works
Ii. In what three ways can we control teenage pregnancy
b. State three reasons why the output energy of machines are less than the input energy.
c. State four causes of corrosion of metals
d. Draw a simple closed electrical circuit
5. a. Give the sources of energy for each of the following electricity generating systems:
I. Hydroelectric dam
Ii. Solar panels
III. Thermal plant
IV..car battery
b. Balance the following equations:
I. Zn+HCl.
Ii. NaOH+ HCI.
III. CaCO3+HCl
c. An atom has a mass number of 22 and atomic number 13. Find the number of neutrons in the atom
d. Explain the following in household wiring
I. Fuse
Ii. Earthing
III. Switch
b. I. Explain why an atom is electrically neutral while ion is not
Ii. Explain why an atom becomes positively charged after loosing electrons
c. State the difference between complete fertilizer and incomplete fertilizer
d. State three difference between mass and weight
Bece science mock episode 8 questions and answers
Solution.
2.i. nitrogen atom.
Ii. Water in clay pot maintains it’s coldness in the dry season despite the weather difference because the clay pot is porous in nature. Some of the water in the pot is absorbed by the pores of the pot. This water absorbed evaporates and create a cooing effect which keeps the water in the pot cool.
b. How electricity is generated by the wind.
The wind turbines use blades to collect the winds kinetic energy wind flows over the blades causing the blades to move. The blades are connected to a drive shaft that turns on the electric generator which produces electricity.
c. Factors that determine the weather of an area
– temperature
– air pressure
– humidity
– wind.
– sunshine
– rainfall
d. Why carbon is important on earth.
Carbon is important on earth because carbon is the main element in compounds which make up the cell and other structures of an organism.
3. a. Characteristics of wet season
– lots of rainfall
– high humidity
– low temperature
Ii. Characteristics of dry season
– low humidity
– lots of sunshine
-High temperature
Uses of instructions
Barometer: to measure air pressure
Wind vane: to measure direction of the wind.
Hydrometer: to measure humidity
c. effects of illegal electric connections in the home.
– can cause electric shock
– overload of power supply
– low current
– fire outbreaks
– damages electric appliance
d. Ten elements on the periodic table
– hydrogen- H
– helium- He
– lithium- Li
– beryllium- Be
– boron- B
– carbon- C
– nitrogen- N
– oxygen- O
– flourine- F
– neon- Ne.
4. a.
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