Answer:
Never smoke near a place where hydrogen is generated or being used. Remove all possible sources of flame and sparks. Hydrogen should only be generated and used in a well ventilated out door area. Precautions must be taken to remove all possibilities of fire or explosion.
<span>There is a direct correlation between the period number and the energy level for valence electrons. For example, the H and He elements, in period 1, have their outer electrons in the energy level "1". This continues down the rows: all the elements in period 2 have their principal energy level as n = 2, period 3 has n = 3, and so on.</span>
(20/23) times 100 is 87%
now the answer asks for percentage ERROR
100-87 =13
so answer is C
80.1 g* (1 cm^(3)/ 2.70 g)= 29.666666... cm^(3).
The calculated volume should have 3 significant figures, so the final answer is 2.97*10^(1) cm^(3)
Hope this helps~
<span>https://quizlet.com/21774816/94-and-95-science-flash-cards
i think uu can find it here lol hope it helps
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