Science Exam 8 February B.docx

‫بسم هللا الرحمن الرحيم‬

‫الجمهورية اليمنية‬ ‫مكتب التربية والتعليم في منطقة السبعين‬

Subject:-------Science-------Name:------------------------------

‫وزارة التربية والتعليم‬ ‫مدارس العز االهلية‬

Class:---------------8-----------------

 First question: Write true (T) or false (F): a) b) c) d) e) f) g) h) i) j)

A cell pushes electrons from away from the positive end and towards the negative end ( A voltmeter is used to measure current ( ) A bigger voltage in a circuit makes a bigger current flow ( ) Adding more cells in series increase the voltage ( ) adding more components makes the current bigger ( ) Calcium sulfate is not a salt ( ) Citric acid is found in lemon fruit ( ) Carbon dioxide react with water to form hydrochloric acid ( ) The chemical formula of hydrochloric acid is H2SO4 ( ) The chemical formula of calcium sulfate is CuSO4 ( )

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 Second question: Fill in the blanks: a. b. c. d. e. f. g. h. i. j.

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Connecting circuits in …………………. means connecting them side by side Connecting circuits in …………………. means connecting them end-to-end Metals conduct electricity because they contain …………………… which are free to move Electric current can flow through ………………. but not through …………….. The electrons in metals are ………………… attached to their atoms A cell pushes electrons from away from the ………….…….. end and towards the …………………. end A voltmeter is used to measure ………………. A bigger voltage in a circuit makes a bigger ………………… flow. Adding more ………………… in series increase the voltage, adding more components makes the ………………… smaller

 Third question: a. Draw two circuits, one has three lamps connected in series and the other has three lamps connected in parallel

b. What makes metal conduct electricity?

c. Complete the following equations: 1. Acid + Alkali  …………………… + …………………… 2. Hydrochloric acid+ sodium  ………………………… 3. Sulfuric acid + calcium carbonate  …………………………………… + ………………. + ………………………. 4. Hydrochloric acid + potassium hydroxide  …………………………..…………… + ………………… 5. Lithium oxide + water  ………………………..

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