Look it up online you will find it
PH = -log [H+]
pH = -log (1.0x10^-4) = -(-4) = 4 or A
Isotopes of any given factor all incorporate the equal variety of protons, so they have the identical atomic wide variety (for example, the atomic wide variety of helium is usually 2). Isotopes of a given factor include exceptional numbers of neutrons, therefore, special isotopes have special mass numbers.
D, Neon and argon are both noble gases and contain almost the same elements.
Answer:
The type of reaction for the following equation is combustion equation.
Explanation:
Combustion reaction is defined as the chemical reaction in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide gas and water molecule.

The reaction given to us:

When 1 mole of ethane reacts with 7/2 moles of oxygen gas it gives 3 moles of water and 2 moles of carbon dioxide gas.
The type of reaction for the following equation is combustion equation.