The way metals like sodium, magnesium and iron react with air and water, is an indication of their relative positions in the 'activity series'. Is this statement true ? Justify your answer with examples.

Reactive metals like potassium and sodium react gently with cold water to liberate hydrogen. (True / False)

When a few drops of phenolphthalein are added to a dilute solution of sodium hydroxide, a pink colour is produced. What will be the colour of the final mixture when excess of HCI is added to it ? (jusify your answer) Arrange the metals iron, magnesium, zinc and copper in the increasing order of their reactivity. What will be the two observations made by the student when iron filings are added to copper sulphate solution ?

From the metals copper, iron, magnesium, sodium and zinc, select from metal which does not react with cold water but reacts with steam when heated.

(a) How does the atomic size vary on going down form top to bottom in a group of the periodic table? Why does it vary this way? (b) Lithium, sodium and potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms fo these elements? Explain your answer.

In each of the following questions, one or two statements is/are given followed by two conclusions I and II. You have to consider the statements to be true, even consider the statement to be tue, even if it seems to be at variance from commonly known facts. You are to decide which of the given conclusions can definitely be drawn from the given statement. Indicate your answer. Statements : Cactus plants are fleshy but need least water. Conclusions : I. All fleshy plants are cactus. II. Cactus plants need least water.

In each of the following questions, two statements are given followed by conclusions / inferences. You have to consider the statement to be true, even if it seems to be at variance from commonly known facts. You are to decide which of the given conclusions /inferences can definitely be drawn from the given statement. Indicate your answer. Statements: (I) All the watches sold in that shop are made of white metal. (II) Some of Rico watches are sold in that shop. Inferences: 1. All watches of white metals are manufactured by Rico. 2. Some of Rico watches are of white metal. 3. None of Rico watches are of white metal. 4. Some of Rico watches of white metal are sold in that shop.

One/Two statements (s) is/are given followed by two conclusions, I and II. You have to consider the statement(s) to be true, even if it/they seems (s) to be at variance from commonly known facts. You have to decide which of the given conclusions can definitely be drawn from the given statement(s). Indicate your answer. Statement : (a) All students like excursions. (b) Some students like laboratory experiments. Conclusions : I. Students who like laboratory experiments also like excursions. II. Some stuents do not like laboratory experiments but like excursions.