D. How the pull of gravity has changed.
The Sun is currently a main sequence star and will remain so for another 4-5 billion years. It will then expand and cool to become a red giant, after which it will shrink and heat up again to become a white dwarf. The white dwarf star will run out of nuclear fuel and slowly cool down over many billions of years.
Answer:
Charge= -2.
Gains two electron into the 4p^4 to become 4p^6.
Explanation:
The element in the periodic table/chart that matches with the valence electron configuration is Selenium with full electron configuration of [Ar] 3d^10 4s^2 4P^4 which is a non-metal that is found in group 4 of the periodic table/chart.
Selenium can receive 2 more electrons on the 4p^4 to give a -2(minus 2) ion that is Se^2-.
Selenium can also loose 2 electron from 4s^2 to give a +2 ion that is Se^2+.
Selenium can also loose 2 electrons from 4s^2 and 2 electrons from 4p^4 to form Se^4+.
Selenium can also loose 2 electrons from 4s^2 and 4 electrons from 4p^4 to form Se^6+.
Thus, in order to form a monatomic ion with a charge(we will be making use of the most stable one). Thus, it will gain two more electron since this is easier to become 4s^2 4p^6.
A. Adding a catalyst. A catalyst by definition is a compound that speeds up reaction rates.
Answer:
(C) H3O+(aq) + C2H3O2−(aq) -> HC2H3O2(aq) + H2O(l)
Explanation:
A buffer is a solution of a weak acid and its salt. It mitigates against changes in acidity or alkalinity of a system. A buffer maintains the pH at a constant value by switching the equilibrium concentration of the conjugate acid or conjugate base respectively.
Addition if an acid shifts the equilibrium position towards the conjugate acid side while addition of a base shifts the equilibrium position towards the conjugate base side.