ALKALI METALSBy: Raaghav, Tanmay,Sparsh,Ashley& Arya

WHAT ARE ALKALI METALS?

•Let's go to the left side of the periodic table. When looking for families, the first one you will find is the alkali metal family of elements. They are also known as the alkaline metals.

HOW MANY ALKALI METALS?

•There are in total 6 alkali metals

•Lithium (Li)•Sodium (Na)•Potassium (K)•Rubidium (Rb)•Cesium (Cs)•Francium (Fr)

Exception

WHERE ARE ALKALI METALS FOUND?

•Alkali metals are found in very common things like salt (SODIUM chloride)•In 1847, German chemist Justus von Liebig discovered potassium in living tissues. As a result, scientists became aware of the role this alkali metal plays in sustaining life: indeed, potassium is present in virtually all living cells. In the human body, potassium—which accounts for only 0.4% of the body's mass—is essential to the functioning of muscles.

WHERE ARE ALKALI METALS FOUND?

Lithium Ion

batteries

PROPERTIES OF ALKALI METALSMelting pointThe alkali metals have low melting and boiling points compared to most other metals. Apart from the other alkali metals, only three metals (indium, gallium and mercury) have lower melting points than lithium. You can see from the graph that lithium, at the top of Group 1, has the highest melting point in the group. The melting points then decrease as you go down the group.

PROPERTIES OF ALKALI METALS

PROPERTIES OF ALKALI METALSBoiling pointThe boiling points of these alkali metals show a similar pattern to the melting points.DensityThe density of a substance is a measure of how much mass it has for its size. It is measured in grams/cubic centimetre. For example gold and lead are very dense metals - even a small lump of either of them can still feel heavy. The alkali metals have low densities compared to most other metals. (They feel lighter.) You can see from the graph that lithium, at the top of Group 1, has the lowest density in the group. The densities then generally increase as you go down the group.

PROPERTIES OF ALKALI METALS

REACTION WITH COLD WATERAll the alkali metals react vigorously with

cold water. In each reaction, hydrogen gas is given off and the metal hydroxide is produced. The speed and violence of the reaction increases as you go down the group. This shows that the reactivity of the alkali metals increases as you go downGroup 1. Metals are going

ALKALI METALS REACTION WITH WATER

LithiumWhen lithium is added to water, lithium floats. It fizzes steadily and becomes smaller, until it eventually disappears.

ALKALI METALS REACTION WITH WATER

SodiumWhen sodium is added to water, the sodium melts to form a ball that moves around on the surface. It fizzes rapidly, and the hydrogen produced may burn with an orange flame before the sodium disappears..

ALKALI METALS REACTION WITH WATER

PotassiumWhen potassium is added to water, the metal melts and floats. It moves around very quickly on the surface of the water. The hydrogen ignites instantly. The metal is also set on fire, with sparks and a lilac flame. There is sometimes a small explosion at the end of the reaction.

HOW IS SALT MADE?All of the alkali metals react vigorously with chlorine gas. Each reaction produces a white crystalline salt. The reaction gets more violent as you move down Group 1, showing how reactivity increases down the group

HOW IS SALT MADE?

SodiumIf a piece of hot sodium is lowered into a jar of chlorine, the sodium burns with a bright yellow flame. Clouds of white powder are produced and settle on the sides of the jar. This is the salt sodium chloride.The reaction of sodium with chlorine is similar to the reaction with lithium, but more vigorous.

REACTIONS DURING MAKING SALT

THANK YOU!People who made this presentation possible:RaaghavTanmaySparshAshley Arya