Acids, Bases and Salts — Science STD 10 — Question

The most abundant metal in the earth’s crust is:

To show that zinc is a more active metal than copper, the correct procedure is to:

A sulphide ore is converted into metal oxide by the process of:

compound → element + element

An element E reacts with water to form a solution which turns phenolphthalein solution pink. The element E is most likely to be:

1. S
2. Ca
3. C
4. Ag

In Mendeleev's periodic table, gaps were left for the elements to be discovered later on. An element which found a vacant place in the periodic table later on is:

1. Be.
2. Si.
3. Ge.
4. Se.

Pb + CuCl₂ → PbCl₂ + Cu
This reaction is an example of:

Structural formula of benzene is:

1. 
2. 
3. 
4. 

An element is soft and can be cut with a knife. It is very reactive and cannot be kept open in the air. It reacts vigorously with water. The element is most likely to be: