Question

Table 11.1
Object is opaque/
transparent/
translucent
Object/material
View through the object
possible (fully/ partially/
not at all)
Pencil
Rubber ball
Sheet of writing paper
Not very sure? some exame of these​

Answer 1

Answer:

The elements in group one of the periodic table (with the exception of hydrogen - see below) are known as the alkali metals because they form alkaline solutions when they react with water. This group includes the elements lithium, sodium, potassium, rubidium, caesium and francium. Each of these elements has just one valence electron, which means that they form only weak metallic bonds. As a result, they are relatively soft and have low melting points.

The single valence electron is easily lost, making these metals highly reactive. They react vigorously with both air and water - when sodium comes into contact with water, for example, it reacts violently to form sodium hydroxide and hydrogen. The heat of the reaction actually ignites the hydrogen! Alkali metals also readily combine with the elements of group seventeen (chlorine, fluorine, bromine etc.) to form stable ionic compounds like sodium chloride.

Explanation: