C.
This is basically the definition of percent composition which is how much mass a element contributes to a specific molecule.
4 get of helium is 1 mole
The new volume of the bag will be 789.5 mL.
<u>Explanation:</u>
As per the Charles law, at constant pressure the volume of the gas is directly related to its temperature in Kelvin (K). That is as the temperature increases, the gas expands and vice-versa.

V1 = 250 ml
V2 = ?
T1 = 19° C
T2 = 60° C
Now we have to rewrite the equation to get the new volume as,
V2 = 
=
<em> </em>= 789.47 ≈ 789.5 ml.
So the new volume of the bag will be 789.5 mL.
The shape of the sp3 orbitals is tetrahedral.
<h3>What are orbitals?</h3>
The term orbital refers to a region in space where there is a high probability of finding the electron. We know that sometimes orbitals could be combined in order to obtain the orbitals that are suited in energy to participate in chemical bonding. This is known as the hybridization of orbitals.
The sp3 orbital is a hybrid orbital The four hybrid orbitals are directed towards the corners of a regular tetrahedron. Hence the shape of the sp3 orbitals is tetrahedral.
Learn more about shapes of orbitals:brainly.com/question/11793076
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