7. A 27.8 L balloon is filled with 7.52g of gas X and placed next to a 27.8 L balloon filled with helium.
Given that Helium has a density of 0.179g/L, which statement correctly explains the movement of the balloons
with valid justification?
a) The balloon filled with helium will float higher because helium is less dense than gas X
b) The balloon filled with gas X will float higher because gas X is less dense than helium
c) Both balloons will float to the same level because their densities are the same
d) Both balloons will float to the same level because their volumes are the same
e) There is not enough information to determine the movement of the balloons

a) The balloon filled with helium will float higher because helium is less dense than gas X

Explanation:

Since gases are known to not have fixed density, they take up the density of their containers, let us find the density of the gas in first balloon.

 Density is the mass per unit volume;

         Density  =  

Insert the parameters and solve;

    mass of gas  = 7.52g

     volume of the gas  = 27.8L

          Density  =   = 0.271g/L

Let us compare the two densities;

 Density of gas  = 0.271g/L

 Density of helium  = 0.179g/L

We see that the density of the gas is higher than that of helium, so, it not float as high as the balloon with helium. The balloon with helium is lighter.

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.  

the correct answer would be d. hope this !