Describe the general properties of group 1 elements.

Group 1 elements, also known as alkali metals, are highly reactive, soft metals with low melting and boiling points.

Group 1 elements, or alkali metals, include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr). These elements are located in the first column of the periodic table and share similar chemical properties due to having one electron in their outermost energy level. This makes them highly reactive, especially with water and oxygen. They are so reactive that they are usually stored in oil to prevent them from reacting with moisture in the air.

These elements are soft metals, which means they can be easily cut with a knife. Their softness increases as you move down the group, with caesium and francium being the softest. They also have low densities, with lithium, sodium, and potassium being less dense than water. This is why these metals float on water, a property not common among metals.

Group 1 elements have low melting and boiling points compared to other metals. These points decrease as you move down the group, meaning francium has the lowest melting and boiling points of the alkali metals. This is due to the increasing atomic size and decreasing strength of the metallic bonds as you move down the group.

In terms of their electronic configuration, all alkali metals have one electron in their outermost energy level. This makes them highly reactive as they tend to lose this electron to achieve a stable electronic configuration. This results in them forming +1 ions and having an oxidation state of +1 in their compounds.

Finally, alkali metals are very good conductors of heat and electricity. This is due to the presence of free electrons which can move and carry charge or heat energy. Despite their reactivity and softness, these properties make them useful in various applications, such as in batteries and heat transfer systems.