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Complete the following flow chart.
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In the modern periodic table, the positions of 1 to 20 elements are shown here. Identify the elements A and B. Write their atomic number.
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Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
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Distinguish between:
s-block - p-block
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Distinguish between:
Group 17 - Group 18
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An X element with atomic number 11 and Y element with atomic number 13 belongs to the third period in the modern periodic table. With this information, give the answers of the below questions.
- Which element has more metallic character from these two elements?
- What is the valency of each X and Y elements?
- Atom size of Y element is smaller than atom size of X element. Explain.
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Position of A, B and C three elements is given in the table from the modern periodic table. Answer the following questions.
| Periods | Group 2 | Group 17 |
| 2 | ----- | A |
| 3 | B | ----- |
| 4 | ----- | C |
- What is A element metal or nonmetal?
- Which is the outermost orbit of element B?
- Identify C element and it's physical state.
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What is electrolysis?
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Explain the reaction given in the figure.
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Find the power of a convex lens of focal length of + 25 cm.
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If focal length of a convex lens is 20 cm at what is the power of the lens?
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Observe the given figure and answer the following questions.
- Where is the above type of lens construction used?
- What type of image is formed by an objective lens?
- What happens instead of placing at Fo if the object is placed in between O and Fo?
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Explain structure of modern periodic table in short.
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Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Oxidation means losing electrons then what is reduction?
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Choose the odd one out and write the reason:
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Choose the odd one out and write the reason:
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Observe the given figure of Fleming's Left Hand Rule and write the labels of 'A' and 'B':
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Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
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Read the following paragraph and answer the questions based on it.
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If heat is exchanged between a hot and cold object, the temperature of the cold object goes on increasing due to gain of energy and the temperature of the hot object goes on decreasing due to loss of energy. The change in temperature continues till the temperatures of both the objects attain the same value. In this process, the cold object gains heat energy and the hot object loses heat energy. If the system of both the objects is isolated from the environment by keeping it inside a heat resistant box, then no energy can flow from inside the box or come into the box. |
- Heat is transferred from where to where?
- Which principle do we learn about from this process?
- How will you state the principle briefly?
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When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
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