Helium can be liquefy through a very
low temperature because of the weakness of attractions between the helium
atoms. In addition, helium is a noble gas that has a very weak interatomic London
dispersion forces. Thus, this element would remain liquid at atmospheric pressure
all the way to its liquefaction point going to absolute zero.
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Answer:
Element A = Oxygen
Element H =
Element B = Aluminum
Element J = Magnesium
Element C = Selenium
Element L = Carbon
Element D = Sodium
Element Q = Francium
Element F = Antimony
Element R = Calcium
Element G = Chlorine
Element S = Tellurium
Explanation:
Element A is Oxygen because: oxygen 6 valence electrons
; is a gas at room temperature
; and is transported in blood to cells.
Element H is Neon because: Neon is a noble gas
; qppears as red light when charged with electricity (Neon light signs) and it has the second highest Ionization energy of the elements
Element B is Aluminum because: Aluminum is a metal and its ion has charge of +3. It is also located on the borders of the Metalloid staircase
.
Element J is Magnesium because its ion has charge of 2+ and is isoelectronic with Neon because it loses two electrons to now have 10 electrons.
Element C is Selenium because its ion that has a charge of -2 is formed by gaining two electrons in order to have 36 electrons which is isoelectronic with Kr
ypton
Element L is Carbon because carbon has the smallest atomic radius of any member in the Carbon family because it is the first member of the family and atomic radius increases on going down the group.
Element D is Sodium because its ion has charge of +1 and it has 2 inner core levels
, the 1 and 2 energy levels.
Element Q is Francium because it has the largest radius and lowest ionization energy of any element
Element F is Antimony. It is a member of Nitrogen family and has the second highest ionization energy level in family
.
Element R is calcium because its on has charge of +2 which is isoelectronic with Argon
. Calcium also has atomic radius is larger than Ar
gon.
Element G is Chlorine. It has the second to the smallest radius of elements in the 3rd period as the second to the last element in the period because atomic radius decreases across a period from left to right.
Element S is Tellurium. It has atomic mass larger than Iodine just to the right of it and is found in the 5th period
Answer:
This reaction is exothermic because the system shifted to the left on heating.
Explanation:
2NO₂ (g) ⇌ N₂O₄(g)
Reactant => NO₂ (dark brown in color)
Product => N₂O₄ (colorless)
From the question given above, we were told that when the reaction at equilibrium was moved from room temperature to a higher temperature, the mixture turned dark brown in color.
This simply means that the reaction does not like heat. Hence the reaction is exothermic reaction.
Also, we can see that when the temperature was increased, the reaction turned dark brown in color indicating that the increase in the temperature favors the backward reaction (i.e the equilibrium shift to the left) as NO₂ which is the reactant is dark brown in color. This again indicates that the reaction is exothermic because an increase in the temperature of an exothermic reaction will shift the equilibrium position to the left.
Therefore, we can conclude that:
The reaction is exothermic because the system shifted to the left on heating.
The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
Thus, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Yes it’s adokngd the formula one
