Why is it important for dna to be duplicated before mitosis

Brainliesttt me asap! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

How many atoms of mg are present in 97.22 grams of mg? 6.022 × 1023 2.408 × 1024 4.818 × 1024 5.855 × 1025