Answer:
Transition elements
Step-by-step explanation:
Transition elements occupies the middle section of the periodic table. Generally, transition elements are metallic in nature. Examples of transition elements are scandium, titanium , vanadium, copper, cobalt, zinc , chromium, manganese , iron etc. Since transition elements are all metallic they are hard , lustrous , are good conductor of electricity and heat and have a high melting and boiling points .
Transition metals are also used as catalyst in many reactions. Transition metals have high densities compare to alkali and alkali earth metals. Transition element are less reactive compare to other metallic elements like the alkali and alkaline earth metals .
Transition metals are usually less reactive and they rarely react with oxygen in air . This resistance account for it noncorrosive nature. Example of this noncorrosive transition metals are silver, Titanium, chromium, manganese, copper etc .
Alkali and alkali earth metals are very reactive so they are likely corrosive. Metalloids don't have high densities and strength.