Question

Two elements A and B have atomic numbers 11 and 17 respectively. To which period of the modem
periodic table do these two elements belong? What type of bond will be fomed between them and why?
Also give the chemical formula of the compound formed.​

Answer 1

Answer:period 3

Ionic bond

NaCl

Explanation:element A is a metal and element B is a non metal and metal react with non metal to form ionic bond.Element A is sodium(Na) and element B is chlorine(Cl)

Reaction between the elements

Na +Cl = NaCl

Answer 2

Answer:

Sodium and magnesium are very electropositive elements and oxygen is electronegative. Electropositive elements often form salt with electronegative elements. Na2O and MgO are basic oxides. It takes more energy to break these oxides as they are held by strong attractions. MgO is also known as magnesia which is a white hygroscopic mineral. Na2O is used in ceramics and glasses. Magnesium oxide is used in treatment of indigestion or as a laxative to relieve occasional constipation. It is also used as a supplement to maintain adequate magnesium in the body.

Explanation:

Hint: We know that we can identify the given elements by their atomic number with the help of a periodic table. We can compare the metallic properties of elements with the help of the trends of periodic tables. So let's identify the elements first.

• So the elements with atomic numbers 11 and 12 are sodium and magnesium respectively and the element having the atomic number 8 is oxygen. We know from the trends of the periodic table that metallic character decreases across a period so sodium exhibits a higher metallic character than magnesium.
• When sodium is heated and then put in a jar full of oxygen it produces a lot of energy and heat. After the reaction sodium oxide with the chemical formula, Na2O is left over in the jar in the form of white powder. Magnesium metals burn very easily in the air. When magnesium reacts with oxygen it forms magnesium oxide with the molecular formula MgO. This is an exothermic reaction where energy releases during the reaction.
• Hence the molecular formula of the compounds formed when elements A and B which is Na and Mg react with the element ‘Z’ having atomic number 8 which is oxygen is Na2O and MgO.