L esson one
Q.1: Write the scientific term:
1- The temperature at which the matter starts to change from a solid state to a liquid state. [----------------------------]
2- The temperature at which the matter starts to change from a liquid state to a gaseous state. [----------------------------]
3- Elements that react with Oxygen when exposed to the humid air.
[----------------------------]
4- Elements that react with Oxygen after a period of time may be several days.
[----------------------------]
5- Materials result from Mixing two metals or more with a certain ratios. [----------------------------]
Q.2: Define each of the following:
- Density: ---------------------------------------------------------------------------
- Melting point: --------------------------------------------------------------------
- Chemical activity for elements: ------------------------------------------------
Q.3: problems:
1. A piece of metal has a mass of 189 gram , volume of 3cm3. Calculate its density.
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2. A cube of a certain material has aside length = 10 cm. Calculate its density.
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3. In an experiment for determination the density, the mass of the used beaker (empty) was 25 gm., the mass of the beaker (containing liquid) was 75 gm, Calculate the density of the liquid if its volume is 50 cm3.
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Q.4: Put () or (x):
1- The volume of 1kg wood is equal to the volume of 1kg silver. ( )
2- The gold, silver and copper alloy is used in making jewels. ( )
3- The heating coils are made from nickel chrome. ( )
4- Acids and Alkalis solutions are good conductors of electricity. ( )
5- Solution of sugar in water and of hydrogen chloride in benzene can't
conduct electricity. ( )
6- Silver, platinum and gold has weak chemical activity. ( )
Q.5: Complete the following:
1- Materials are differing from each other in some characteristics such as ------------------, ------------------- and -------------------
2- Materials that have ------------------ density than water float on it, but materials that have ----------------- density than water sink in it.
3- Light columns are painting from time to time to protect them from ----------
4- ----------------- is an example for the soft solids at ordinary temperature, while -------------------- is an example for substance that need heat to get soften, and ---------------- is an example for substances which can't be soften if heated.
5- Gases are --------------------- conductors of electricity.
Q. 6: Give reason for each of the following:
1- Ice float-in the polar regions-on the surface of water.
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2- The volume of 1 kg wood is larger than volume of 1 kg iron.
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3- Water is not used in extinguishing petrol fires.
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4- It is not right to leave sodium and potassium exposed to the humid air.
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5- The materials that are made form iron are painting with silver and gold, layers.
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6- Both gold and silver are used in making (manufacture) of jewels.
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7-the balloons which rise up in the air are filled with helium or hydrogen gas.
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Q. 7: Choose the correct answer:
1- ------------ is an example of materials that can't be softening by heat.
[Iron – copper – sulphur]
2- The equal volumes for different materials have ---------------- Masses.
[Equal – different – constant]
Q. 8: Different questions:
a. When you put four similar balls in the volume, mass and type in four beakers contain different liquids, the four beakers appears as in following figures:
Arrange the four liquids descending according to their densities.
b. Choose from (a) that is suitable to (b):
A |
B |
1- The measuring unit of density. 2- The measuring unit of Mass. 3- The measuring unit of volume. 4- The measuring unit of length. |
- gram. - Cm. - Cm3. - gm / cm3. |
c. If you know that the density of the natural milk is 10.03 gm/cm3. How can you identify the quality of the milk you have bought.
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d. A graduated cylinder with 25 cm3 of water has put on a plate of the balance and on another plate of the balance there was a graduated cylinder with 25cm3mercury.