I think the correct answer from the choices listed above is the last option. The pressure of an enclosed gas depends on the number of molecules in a unit volume and their average kinetic energy, its chemical composition, the altitude about sea level and the number of atoms per molecule. Hope this helps. Have a nice day.
Answer:
- The standard form of a chemical element is the natural mixture of several isotopes of the same element, which is atoms with the same number of protons but different number of neutrons, while an isotope is a particular kind of atom with a definite number of neutrons.
Explanation:
A <em>chemical element</em> is a pure substance formed by atoms with the same atomic number (number of protons). This is because it is the number of protons what identifies an element.
For example: oxygen is a chemical element, so oxygen is formed by only atoms of oxygen, and the atomic number of those atoms is 8, because every oxygen atom has 8 protons.
Nevertheless, some atoms of oxygen, may have different number of neutrons. Isotopes are different kind of atoms of the same element, which only differ in the number of neutrons. So, some atoms of oxygen will have 8 neutrons, other 9 neutrons, and other 10 neutrons (those are the stable isotopes of oxygen).
That difference in neutrons, is generally accepted that, does not modifiy substantially the chemical properties of the element, but the mass number. So, the isotopes with more neutrons wil be heavier, and the isotopes with less neutrons will be lighter.
- Mass number = number of protons + number of neutrons.
In general a chemical element is formed by a mixutre of isotopes of the same element.
Answer:

Explanation:
Hello there!
In this case, for the described chemical reaction, we can write:

Thus, by considering the 1:2 mole ratio of methane to water, and the molar mass of the latter (18.02 g/mol), the following is useful to calculate the mass of water that is produced:

Which is equal to:

Which is not among the choices.
Regards!
It is a triangular shape and there 26 electrons all together but when shared each individual element has 8