Year 10 General Science – Semester 2 Exam 2013 REVISION
Part A – Chemistry
Name: _______________________________
1. Give 2 differences between physical and chemical changes with examples.
2. Draw a structure of Sodium Atom, find out the
Mass number = ________, Atomic number = _________, Electron number = ______________
Proton number = ____________ and Neutron number = ______________
Electronic Configuration of sodium Atom = ____________
Sodium Ion = ___________ (how it was formed: _____________________________________________
________________________________________________________________________________________________)
3. Name the four main groups of element and describe each of them.
Group 1 = _______________________________________________________________________________________
Group 2 = _______________________________________________________________________________________
Group 7 = _______________________________________________________________________________________
Group 8 = _______________________________________________________________________________________
What is special about the elements in each group?
___________________________________________________________________________________________________
4. Where are the distribution of metals, metalloids and non-metals in the periodic table?
___________________________________________________________________________________________________
___________________________________________________________________________________________________
5. Name the 5 types of chemical reactions with examples
(1) ____________________ - a larger molecule is made from simpler chemicals.
eg. Magnesium + Oxygen ------ > ______________________
(2) ___________________ - a larger molecule is broken down into simpler chemicals.
eg. Calcium carbonate --------- > ___________________________ + carbon dioxide
(3) ___________________– burning of organic compounds with HxHyOz to give carbon
dioxide and water + HEAT ENERGY
eg. Methane gas (CH4) in Bunsen burner. Balance the equation below:
CH4 + O2 --------- > H2O + CO2 + Heat + Light
(4) Singe ___________________ - the more active metal will replace the metal part of the
other compound in solution.
eg. Zinc + Copper sulphate ------ > __________________________ + _____________
(5) ___________________ - a solid is formed from mixing 2 clear solutions.
eg. Lead nitrate + Potassium iodide ------ __________________ + _______________________
6. Formation of gases and testing for gases
Gas
H2
O2
CO2
Preparation
Zinc + Acid
Hydrogen peroxide with
catalyst Manganese dioxide
Acid + Calcium carbonate
Testing
Using a burning splint – give a _________________
________________ a glowing splint
Turns Lime water ________________.
7. Distinguish the 3 main types of Bonding: Ionic, Covalent and Metallic.
Ionic
Between ___________ and
non-metal
Formed by transfer of
electrons
High melting point
Covalent
Between non-metal and
________________.
Formed by _____________
electrons
Low melting point
Metallic
Metal ion surrounded by
valence electrons
High melting point
8. Naming compounds
Chemical Formula
Chemical Name
Total number of Atoms
CaCl2
MgS
Al(OH)3
NaNO3
Al2O3
9. Writing Chemical Formulae
Substance
calcium oxide
magnesium chloride
sulphur dioxide
zinc oxide
ammonia
pure gold
Bonding type
Chemical formula
10. Complete Results by writing down reaction or no reaction
Mg
Cu
Na(NO3)2
Zn
Most
Active
Activity Series
Na
Cu(NO3)2
Pb(NO3)2
AgNO3
Least
Active
Mg
Ca
Zn
Pb
Cu
Ag
Name this type of reaction. When will this take place. Write an equation for one of the
reaction.
___________________________________________________________________________________________________
___________________________________________________________________________________________________
11. Reaction of metals with different chemicals:
Which 3 metals are known as native metals (as they may appear in uncombined
forms)? ___________________, ______________________ and ______________________.
Why is group 1 metals more reactive than group 2?
___________________________________________________________________________________________________
Part B: Astronomy
1. Organisation of the celestial objects in the Universe from smallest to the largest.
Milky Way, Super-cluster, Universe, Earth, Meteoroid, Jupiter, Sun, Local Group, Mars,
Asteroid, Solar System, our Moon.
2. What is the difference between meteor, meteorite and meteoroid?
3. What is a solar system?
4. Special feature of each planet:
No
1
2
3
4
5
6
7
8
Planet?
Special feature
Hottest planet due to CO2 atmosphere
Largest planet protecting our Earth from space rock
Lack of atmosphere, many craters are formed by rocks
Blue planet other than the Earth
Planet with water and oxygen supporting life
Planet with robots and spacecraft landing
Planet with very clear rings of ice
The most distant planet and coldest
5. What is a galaxy? Give the 3 different types of galaxies? Describe our galaxy briefly.
6. What are the 2 opposite forces the control or maintain the integrity of a star? Explain
briefly.
7. What is the Big Bang Theory?
8. What is a LIGHT YEAR? Why is it commonly used in astronomy?
9. The Hertzsprung-Russell diagram:
BRIGHTNESS
TEMPERATURE
Star Brightness Temperature SIZE
SPECTRAL
TYPE
A
B
C
D
10. What are the fates of different stars?
Very small star --- > _______________________________
Average size (like our Sun)
----- > ______________________________
Massive star ----- > ______________________________
Very massive star
----- > ______________________________
Part C : Electricity
1.
Ohm’s Law
Voltage = Current x Resistance
V = IR
I = V/R
R = V/I
a) Find the voltage of the battery if the light bulb has a resistance of 30 ohms and a
current of 1.5 A.
b) Find the resistance of an electric bell drawing 1.2 A current at 6 V?
c) What is the current in a circuit with a motor of 150 ohms at 240V?
2. Power:
P = VI
V = P/I
I = P/V
Unit: Watts (W) or Joules/second
a) What is the voltage of an appliance of 200W when supplied with a current of 5A?
b) 5A is flowing through a vacuum cleaner at 240V. How much power is being dissipated?
c) Find the current flowing through a heater with a Power of 2100 Watts at 240Volts?
3. Power Rating (Watts)
P = E/t
(Energy in Joules) Time in seconds
What is the Power of the Electric Jug is it used 12000 Joules in 15 seconds ?
4. Electricity in KiloWattHours (kWh)
E=PxT
Power in KiloWatts (kW) and Time in Hours
a) What is the total electricity used in kWh of an appliance with 1500 W in 8 hours?
Hint: convert W to KW first.
b) Find the cost of electricity in a month if it is charged at 25cents per kWh.
Assume 30 days in a month.