did u ever get the answer ? I’m also on k12 stuck on this lol
hydrogen combines with sulfur is H2S
<span> hydrogen combines with
oxygen H2O</span>
<span>Hydrogen sulfide<span> <span>is the </span></span>chemical compound<span> <span>with the </span></span>formula <span>H<span>
2S</span></span>. It is a colorless gas<span> <span>with the characteristic foul odor of rotten </span></span>eggs<span>; it is heavier than air, very poisonous,
corrosive, flammable, and explosive; properties shared with the denser </span>hydrogen
chalcogenides</span>
<span> </span>
Answer:
Explanation:
The half-life of Na-24 (15 h) is the time it takes for half of it to decay.
After one half-life, half (50 %) of the original amount will remain.
After a second half-life, half of that amount (25 %) will remain, and so on.
We can construct a table as follows:
No. of Fraction Mass
<u>half-lives t/da Remaining Remaining/g
</u>
0 0 1 18
1 15 ½ 9.0
2 30 ¼ 4.5
3 45 ⅛ 2.2
4 60 ⅟₁₆ 1.1
5 75 ⅟₃₂ 0.56
6 90 ⅟₆₄ 0.28
We see that 
remain after five half-lives (75 h).
Answer:
The correct answer is 0.92 g
Explanation:
The density is defined as the mass per unit of volume:
Density= mass/volume
From the data provided:
volume= 5.4 L
density= 0.17 g/L
Thus, to calculate the mass of helium:
mass= density x volume = 0.17 g/L x 5.4 L= 0.918 g ≅ 0.92 g
I would go with C because that seems like the best answer choice
