The excretory and urinary are not the same because the excretory system is collective for all system performing the function of eliminating waste from the body like excess water,urea, carbon dioxide and lactic acid but the urinary system focuses on removal of excess water and urea from the body
Answer:
Xe
Explanation:
Cs and Na are solids in room temperature while F and Xe are gases.
The number of electrons in the outermost shell of an atom will determine its reactivity. Out of the gases given Xe and F, F ( the most electronegative element) posses 5 valence shell electrons which makes it highly reactive while Xe which is a noble gas posses 8 valence shell electrons which makes it less reactive compared to many elements.
The R group varies, and it is the carbon-phosphate backbone
