Answer:
69.66 g
Explanation:
We have the following from the question;
Density of the substance = 5.4 g/ml
Volume of substance = 12.9 ml
Mass of substance= the unknown
Since we have both density and volume of the substance, the question must be for us to obtain the mass of the substance, hence;
Density= mass/volume
Mass= Density × volume
Mass = 5.4 g/ml × 12.9 ml
Mass= 69.66 g
Answer:
a.
.
b.

c.

Explanation:
Hello,
In this case, considering that the valve is opened, we can use the Boyle's law in order to compute the final pressure of argon by considering its initial pressure and volume and a final volume of 5.0 L:

And the final pressure of helium:

Which actually are the partial pressure of both of them, it means that the total pressure is:
Finally, the mole fraction of each gas is computed by considering the Dalton's law:


Best regards.
C) Has sub levels within the energy levels. Lol forgot to put C
A. Chlorine is the most electronegative element out of the possible choices. Generally (though not 100% of the time) electronegativity increases as you go further left and up the periodic table.
I think the answer is d not real fir sure I'll find out in the morning sorry