The element X forms a compound X₂Y. Suggest an element that Y might be and give reasons for your choice.

An element Y is in second period and group 16 of the periodic table:

(i) Is it a metal or non-metal?

(ii) What is the number of valence electrons in its atom?

(iii) What is its valency?

(iv) What is the name of the element?

(v) What will be the formula of the compound formed by Y with sodium?

An element X has mass number 40 and contains 21 neutrons in its atom. To which group of the periodic table does it belongs?

An element X combines with oxygen to form an oxide XO. This oxide is electrically conducting.

(a) How many electrons would be there in the outermost shell of the element X?

(b) To which group of the periodic table does the element X belong?

(c) Write the formula of the compound formed when X reacts with chlorine.

An element A has an atomic number of 6. Another element B has 17 electrons in its one neutral atom.

(a) In which groups of the periodic table would you expect to find these elements?

(b) What type of bond is formed between A and B?

(c) Suggest a formula of the compound formed between A and B.