SCIENCE AND TECHNOLOGY

An element X is soft and can be cut with the help of a knife. It is very reactive to air and cannot be kept open in the air. It reacts vigorously with water. Identify the element from the following:

Which of the following alloys contains a non-metal as one of its constituents?

Galvanisation is a method of protecting steel and iron from rusting by coating them with a thin layer of

Which of the following pairs of reactants will go undergo a displacement reaction?

Which among the following is the most abundant metal found in the earth’s crust?

Which of the following pairs will give displacement reactions?

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

Which of the following represent the correct order of decreasing reactivity?

In the given reaction, Al₂O₃ + NaOH → ……X…… + H₂O
What is element X?

In electrolytic refining, the cathode is made up of

The sulphide ores are converted into oxides by heating strongly in the presence of excess air. This process is known as

The metal which is liquid at room temperature is

Bauxite is an ore of

The number of protons in an atom of an element A is 19 then, the number of electron in its ion A+ is:

The non-metal which is liquid at room temperature is: