How can I figured out if molecular polarity is polar or non-polar?

Write a balanced equation showing the formation of copper (ii) nitrite from its elements

What is the most common reason for matter changing its state?

With the largest atoms and the smallest number of valence electrons and with the smallest atoms and the greatest number of valence electrons are the most reactive. a. nonmetals; metals b. nonmetals; transition elements c. transition elements; metals d. metals; nonmetals