Answer:
Kelvin
Explanation:
As we know that

Where P is the pressure in atmospheric pressure
T is the temperature in Kelvin
R is the gas constant
V is the volume in liters

Substituting the given values in above equation, we get -

On rearranging, we get

Kelvin
I believe the answer would be A. Electronegativity increases across a period.
Answer:
That iron atom is oxidized. It loses two electrons.
Explanation:
Compare the formula of an iron atom and an iron(II) ion:
- Iron atom:
; - Iron(II) ion:
.
The superscript
in the iron(II) ion is the only difference between the two formulas. This superscript indicates a charge of
on each ion. Atoms and ions contain protons. In many cases, they also contain electrons. Each proton carries a positive charge of
and each electron carries a charge of
. Atoms are neutral for they contain an equal number of protons and electrons.
Protons are located at the center of atoms inside the nuclei. They cannot be gained or lost in chemical reactions. However, electrons are outside the nuclei and can be gained or lost. When an atom loses one or more electrons, it will carry more positive charge than negative charge. It will becomes a positive ion. Conversely, when an atom gains one or more electrons, it becomes a negative ion.
An iron atom
will need to lose two electrons to become a positive iron(II) ion
with a charge of
on each ion. That is:
.
- Oxidation is Losing one or more electrons;
- Reduction is Gaining one or more electrons.
This definition can be written as the acronym OILRIG. (Khan Academy.)
In this case, each iron atom loses two electrons. Therefore the iron atoms here are oxidized.
Atoms with the same number of protons, but different numbers of neutrons are isotopes of the same element.
Answer:
2H2 + O2 -----> 2H2O
Not sure about the second question though.