I think that the answer is 0.49
Classification of the Elements. The next thing in our review is to classify the elements into three groups. These three groups are: metals, nonmetals, and inert gases. Let's look at where these groups are located on the periodic table and correlate them with the ability to lose and gain electrons.
Arsenic, I believe. Metalloids fall in between metals and nonmetals (usually on the bold line separating the two on the periodic table). And since the metalloid in question has four electron shells and five valence electrons in the outermost shell, you can see that this element is arsenic
Answer:
It's B
Explanation:
A is going to evaporate more quickly causing it to push through the tube to beaker B.
Answer : The rate of consumption of oxygen = 0.245 mol/s
Solution : Given,
Rate at which Hydrogen burns = 0.49 mol/s
The Reaction is,

In this reaction, 2 moles of hydrogen react with the 1 mole of oxygen.
The rate at which oxygen burns is equal to the half of rate at which hydrogen burns.
Rate at which Oxygen burns =
× 0.49 mol/s
= 0.245 mol/s