Q1. A. Fill in the blanks.
1.        The formula of chloride of metal M is MCl2. The metal M belongs to group ______
2.        The arrangement of elements in a group of three is known as ­________.
3.        The element eka – aluminum in Mendeleev’s periodic table is known as _________in modern periodic table.
4.        The chemical formula of POP is_________.
5.        Corrosion can be prevented by using____________.
6.        The chemical reactions is which heat is liberated are called _________reactions.
7.        Phenolphthalein is __________type of indicator.
8.        pH scale ranges from ________to_________ 
9.        Sodium or potassium salts of higher fatty acids are termed as _________
10.     10% NaCl is known as__________.
Q2. Write short notes on
1.        pH scale (with proper diagram).
2.        Water of crystallization (with proper example)
Q3. Answer the following questions.
  1. State application (uses) of baking soda.
  2. In modern periodic table, which are the metals, non metals and metalloids among the first 20 elements?
  3. Define atomic size. How does it vary in a period and in a group?
Q4. Give Scientific reasons.
1.        Physical states of reactants and products are mentioned while writing a chemical equation.
2.        Iron articles rust readily whereas steel which is also mainly made of iron will not undergo corrosion.
3.        Edible oil is not allowed to stand for a long time in air.  
4.        Metallic character decreases from left to right in a period.