Need help with this please.

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

Label a-f based on the table using c for concentrated and d for dilute

Write the formula for the following chemicals. 7. e. trinitrogen tetraoxide a calcium phosphate f. magnesium acetate b. potassium sulfide g nickel(iii) cyanide c carbon dioxide h. silver sulfate d. cobalt(ii) chloride