Q.1. Fill in the blanks. (Marks: 5)

1. The device used to measure electric current is called ____________________.
2. The chemical formula for common salt is ____________________.
3. Mitochondria is known as the ____________________ of the cell.
4. The phenomenon of light bending as it passes from one medium to another is called ____________________.
5. An acid turns blue litmus paper to ____________________.

Q.2. Match the following pairs. (Marks: 5)

Q.3. Answer the following in one or two sentences. (Marks: 10)

1. What is a neutralization reaction?
2. State Fleming's left-hand rule.
3. Define heredity.
4. Why does the sky appear blue?
5. What are the functions of blood platelets?

Q.4. Differentiate between the following. (Any 2) (Marks: 6)

1. Arteries and Veins
2. Metals and Non-metals
3. Renewable and Non-renewable sources of energy

Q.5. Classify the following into acids and bases. (Marks: 4)

(HCl, NaOH, H₂SO₄, KOH, HNO₃, Ca(OH)₂, CH₃COOH, Mg(OH)₂)

Q.6. Answer the following questions in detail. (Any 3) (Marks: 15)

1. Explain the structure and function of the human heart with a labeled diagram.
2. What is corrosion? Write three methods to prevent it.
3. Describe the structure of a neuron and explain how nerve impulses travel.
4. State Ohm's law. Draw the circuit diagram and derive the formula for resistors in series.

Q.7. Write short notes on the following. (Any 2) (Marks: 10)

1. The Food Chain
2. The Modern Periodic Table
3. Reflex Action