Answer : The correct option is, (C) 2, 4 and 5.
Explanation :
Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.
For example : Methane react with oxygen to give carbon dioxide and water.

In the given list of chemical substances,
are in oxide form. They can not be both reactant and product of a single combustion reaction.
In the given list,
is the only hydrocarbon which shows a combustion reaction. That means
react with
to give
and
as a product.
The balanced combustion reaction of
is,

Therefore, the correct answer is, (C) 2, 4, and 5.
C funnel because the funnel would have a large enough entrance to put a solid through
N = given mass/ molar mass.
n = number of moles
given mass = 2.47 g
molar mass = 197 g/mol
n = 2.47 / 197
n = 0.01253 moles.
I'm sure you wanted to ask more than this. Just put some comments in. I can do the same.
Your answer to your question is: 1s² 2s² 2p⁶
Answer:
C.) No. of electrons
Explanation:
A.) is incorrect. The atomic number represents the number of protons in an element. Nitrogen (N) and sodium (Na) always have a differing amount of protons.
B.) is incorrect. The mass number represents the number of protons and neutrons in an element. The number of neutrons and protons are specific to each element (disregarding isotopes). When elements ionize, these amounts are not altered.
C.) is correct. When an element becomes an ion, the number of electrons change. When nitrogen gains 3 electrons and sodium loses 1 electron, they end up having the same number of electrons (10).
D.) is incorrect. When elements ionize, the number of neutrons does not change. The only way two different elements could have the same number of neutrons is if at least one of the elements is an isotope. Isotopes are two or more atoms of the same element that differ in their amounts of neutrons.