Answer:
She will use one 2 as a subscript.
Explanation:
Nitrogen is a chemical element with the symbol "N" and has an atomic number of 7. Thus, it is found in group (5) of the periodic table and as such it has 5 electrons in its outermost shell. Therefore, nitrogen has two (5) valence electrons.
On the other hand, oxygen has an atomic number of 8 and with the symbol "O."
When nitrogen and oxygen react chemically, they produce a compound known as nitrogen dioxide
In this scenario, Jenny is studying a compound that has two oxygen atoms and one nitrogen atom. Therefore, the statement which describes the subscripts she will use to write the chemical formula is, she will use one 2 as a subscript.

Where: 2 represents the subscript of oxygen.
Answer:
It would be hard to test scientifically since it's subjective and can only be proven true if you conducted some experimentations and observations.
Answer:
B . energy cannot be created or destroyed
Answer:
The acceleration is 0.
Explanation:
The formula for acceleration is:
a = (v-u)/t
If v and u are equal, thus it would be 0 when subtracted, and anything divided by 0 is 0.
Answer:
2.41 L
Explanation:
We can solve the problem by using the ideal gas equation, which can be rewritten as:

where we have:
(initial pressure is stp pressure)
is the initial volume
is the initial temperature (stp temperature)
is the final pressure
is the final volume
is the final temperature
By substituting the numbers inside the formula and solving for V2, we find the final volume:

which corresponds to 2.41 L.