The rows are the one line of elements that goes from left to right horizontally. A column is a line of elements that goes vertically.
To work this out you do 400÷20=20
Conductivity, malleability, and high melting points. Hope this helps :)
Answer:
Sodium Fluoride F 18 Injection is a positron emitting radiopharmaceutical, no-carrier added.
Explanation:
Element Name Fluorine
Element Symbol F
Atomic Number 9