Which two types of chemical reactions do not always occur? What, specifically, do you need to do to see if they occur or not

When you mate two plants together the terms is called? answer it fast as possible plz! i have a test tomorrow!

Solutions of sodium carbonate and silver nitrate react to form solid silver carbonate and a solution of sodium nitrate. a solution containing 3.50 g of sodium carbonate is mixed with one containing 5.00 g of silver nitrate. how many grams of sodium carbonate, silver nitrate, silver carbonate, and sodium nitrate are present after the reaction is complete?

Some animals that try to adapt to climate changes eventually die due to starvation, as climate change alters the web.