Metals and Non-Metals — Science STD 10 — Question

The atomic numbers of the three elements X, Y and Z are 2, 6 and 10 respectively.

1. Which two elements belong to the same group?
2. Which two elements belong to the same period?

Give reasons for your choice.

What is observed when a solution of sodium sulphate is added to a solution of barium chloride taken in a test tube? Write equation for the chemical reaction involved and name the type of reaction in this case.

How does the atomic size vary on going down from top to bottom in a group of the periodic table? Why does it vary this way?

A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?

What are the raw materials required for making soap in a laboratory (or at home)?

Why do we store silver chloride in dark coloured bottles?

Hydrogen is not a metal but still it has been assigned a place in the reactivity series of metals. Why?

Name the acid present in ant sting and give its chemical formula. Also give the common method to get relief from the discomfort caused by the ant sting.

Why are the metals like Na, K, Ca and Mg never found in their free state in nature?

Explain the action of baking powder in the making of cake (or bread). Write equation of the reaction involved.