Potassium oxide is an ionic compound formed by combining potassium and oxygen. It carries the chemical formula K2O. Potassium cannot be found free because it is too reactive. It has valency +1 and combines readily with oxygen atoms forming K2O.

Potassium nitride

Potassium Nitride

This is a combination reaction. To balance the equation, the first thing to do is to change the coefficient in front of K2O if and and to balance the oxygen atoms. Put a 2 in front of K20. Next change the coefficient in front of the potassium (K).

K2O

Potassium metal reacts very rapidly with water to form a colourless basic solution of potassium hydroxide (KOH) and hydrogen gas (H2). The reaction continues even when the solution becomes basic.

When any substance burns in oxygen it is called a combustion reaction. Potassium (lilac) burns most vigorously followed by sodium (orange-yellow) and then lithium (red), as you might expect.

Potassium reacts with oxygen to form K2O2 and KO2 only.

Potassium oxide is produced from the reaction of oxygen and potassium; this reaction affords potassium peroxide, K2O2. Other possibility is to heat potassium peroxide at 500 °C which decomposes at that temperature giving pure potassium oxide and oxygen.

Potassium and sodium are soft metal which are easily cut exposing a shiny surface which changes to dull rapidly.

Metallic potassium is available commercially for about $40/lb in small quantities….

Freshly cut sodium metal has a bright, shiny surface that quickly becomes a dull gray as it reacts with oxygen in the air around it. Over time, the metal becomes covered with a white crust of sodium oxide that prevents further reaction of the metal and oxygen.

The chemical symbol K comes from kalium, the Mediaeval Latin for potash, which may have derived from the arabic word qali, meaning alkali. Potassium is a soft, silvery-white metal, member of the alkali group of the periodic chart.

K

The elements of the periodic table sorted by name in an alphabetical list.

Nitrogen

Periodic Table Scavenger Hunt Part 2

Ca

• francium. The heaviest of the alkali metals is very rare and radioactive and has a very short life span (about 22 minutes).
• cesium. Rare metal that is used especially in photoelectric cells, atomic clocks, infrared lamps and treating certain cancers.
• rubidium.
• potassium.
• sodium.
• lithium.

John Newlands

Can you now say why Mendeleev’s choice of formulae of compounds as the basis for deciding the position of an element in his Table was a good one? Ans: Mendeleev developed a periodic table of elements where in the elements were arranged on the basis of their atomic mass and also on the similarity on chemical properties.

1. Why are the elements no longer organized by atomic mass? The elements in the periodic table is arranged by the atomic number because the chemical behavior of the element is determined by the number of protons, not so much because of the protons, but becausein a neutral atom, there are a matching number of electrons.