Answer:
<em>ii</em><em> </em><em>and</em><em> </em><em>iv</em><em> </em>
Explanation:
atomic mass is the sum of protons and neutrons
protons ( postively charged) usually have the same number like electrons( negatively charged)
Convection is when cool air sinks and warm air rises. i am not 100% sure though
Answer: four hundred and 18
Explanation:
Simple math showed that only 16 words are possible from a two-letter combination, but a three-letter code produces 64 words. Operating on the principle that the simplest solution is often correct, researchers assumed a three-letter code called a codon.