Questions

An electrically charged atom or group of atoms formed by the loss or gain of one or more electrons is called an Ion.

Cation:

An ion is a cation (positive ion) if it is created by electron loss and is attracted to the cathode in electrolysis.

Anion:

An ion is an anion (negative ion) if it is created by an electron gain and is attracted to the anode.

The valence of an ion is equal to the number of electrons lost or gained and is indicated by a plus sign for cations and a minus sign for anions.

Ex: Na +, Cl−, Ca ++,...

The name India is originally derived from the name of the river Sindhu (Indus River).

Nitrous acid act as an oxidising agent because it oxidises potassium iodide to iodine. It is also a reducing agent because it decolourises acidified potassium permanganate solution.

Nitric acid acts only as an oxidising agent

Ammonia acts only as a reducing agent

Nitrogen peroxide acts only as an oxidising agent.

Ionic character depends on the electronegativity difference between the bonding elements. The greatest the elctronegativity diffference the greatest the ionic character.

Here in the given options, H-F has has the greatest ionic character. The electronegativity of Hydrogen is 2.1 and that of Fluorine is 4. Now the electronegativity difference is 4 - 2.1 = 1.9.

First Jim and Jeanne walks across the bridge, it takes 2 minutes. 

Jim walks back with the torch light, which takes 1 minute. 

Then Louis and Anne walk on the bridge, which takes 10 minutes.

Jeanne comes back with the torch light, it takes 2 minutes.

Finally Jim and Jeanne walks across the bridge, which takes 2 minutes.

Total = 2 + 1 + 10 + 2 + 2 = 17 minutes