No.
It is an import into the English language from Latin and is - nowadays - confined to mathematical or philosophical discussions.
The most common word used in a conversation is typically "I" or "you", as these are often used to refer to oneself or the listener. Other common words include "and", "the", "it", and "is".
Ergo is just another word for therefore, or hence. Technetium as a pure element is virtually nonexistent in nature, ergo it was one of the last elements to be identified.
The most common choice for a Latin equivalent to the English 'therefore' is ergo. The Latin term most often is rendered into English as 'accordingly,' 'consequently', 'then', or 'therefore'. This is its use as an adverb. The word 'ergo' also has a use as a preposition. In that use, it's translated as 'on account of, because of'.
Therefore
About 5 to 6 times.
Thus , ergo ,
"Chill" is a common word used in informal conversation to mean relaxed, calm, or easygoing. It can also be used to suggest taking it easy or not getting stressed out about something.
21 can not be divided by 2, ergo it can not be a common factor with 72
hence
yes
No, the label "archaic" means that a word is no longer in common use and is considered outdated or old-fashioned. It is not related to the formality or casualness of its usage in writing or conversation.
Ergo, as a preposition, means on "account of" or "because of." And as an adverb "therefore."