Questions

Concatenation of text means adding a word with other word. It can be done using Ampersand (&).

For example :

'Amper' & 'sand' = Ampersand 

A bureaucracy is a way of administratively organizing large numbers of people who need to work together.

The term bureaucracy literally means "rule by desks or offices".

Organizations in the public and private sector, including universities and governments, rely on bureaucracies to function.

A manometer is used to measure a pressure difference between two points.

The Length of the Day is determined in Astronomical Units.

The length of a day corresponds to the time the Earth takes to turn around on its axis, which is approximately 24 hours. But it's not exactly 24 hours. 

This phenomenon is due to tides raised by the Moon which slow Earth's rotation. Because of the way the second is defined, the mean length of a day is now about 86 400.002 seconds, and is increasing by about 1.7 milliseconds per century.

A metalloid is an element with properties between metals and non metals or the mix of both.

The six metalloids are arsenic, silicon, germanium, boron, antimony and tellurium.

Hence, silicon is the only metalloid in the given list.