Answer:
FALSE!
Explanation:
Gymnosperms do use seeds but are exposed like the pine cones of pines. Angiosperms still have seeds, however, they flower or fruit.
Enthalpy of formation is defined as the heat change that is needed for formation of one mole of substance from its constituent elements in pure state.
In present case, Heat of formation of one mole of C2H6 at <span>101.3 kpa and 298 k is -84 kJ/mol. Negative sign indicates that, heat is evolved from the system.
Thus, for two mole of ethane, heat of formation will be 2 X (-84) = -168 kJ/mol.
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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.
opinion and belief mean a judgment that someone thinks is true. ... belief is used if the judgment is certain and firm in a person's own mind without regard to the amount or kind of evidence.