<span>According to octet rule, atoms with an atomic number less than 20 tend to combine with other atom such that both of these atoms have eight electrons in their valence shells, which gives them the same electronic configuration as that of noble gas.
However, there are few compound that donot obey octel rule. Among the elements mentioned above i.e. oxygen and helium obeys octet rule.
In case of nitrogen, oxide of nitrogen (like NO and NO2) have incomplete octet.
While there are few compounds of Br wherein Br has expanded octet. For example, in BrF5, Br has 12 electrons in valence shell. </span>
This question is missing the part that actually asks the question. The questions that are asked are as follows:
(a) How much of a 1.00 mg sample of americium remains after 4 day? Express your answer using 2 significant figures.
(b) How much of a 1.00 mg sample of iodine remains after 4 days? Express your answer using 3 significant figures.
We can use the equation for a first order rate law to find the amount of material remaining after 4 days:
[A] = [A]₀e^(-kt)
[A]₀ = initial amount
k = rate constant
t = time
[A] = amount of material at time, t.
(a) For americium we begin with 1.00 mg of sample and must convert time to units of years, as our rate constant, k, is in units of yr⁻¹.
4 days x 1 year/365 days = 0.0110
A = (1.00)e^((-1.6x10^-3)(0.0110))
A = 1.0 mg
The decay of americium is so slow that no noticeable change occurs over 4 days.
(b) We can simply plug in the information of iodine-125 and solve for A:
A = (1.00)e^(-0.011 x 4)
A = 0.957 mg
Iodine-125 decays at a much faster rate than americium and after 4 days there will be a significant loss of mass.
The atom contain 6 neutrons, if that's the question
Answer:
87.27 grams
Explanation:
The mole ratio of nitrogen to hydrogen is 1:3; while that one of hydrogen to the products (ammonia) is 3:2
Thus if 3 moles of hydrogen gas produce 2 moles of ammonia gas
7.7 moles of hydrogen will produce:
(7.7moles×2)/3
77/15 moles
1 mole of ammonia gas has a mass of 14+3=17
since the mass of an atom of nitrogen is 14 while that of hydrogen atom is 1.
Therefore 77/15 moles will have a mass of
77/15 moles × 17=87.27 grams
Answer: D. CYTOKINESIS
Explanation:
Mitosis<em> </em>ends<em> with telophase, or the stage at which the chromosomes reach the poles. ... Telophase is followed by </em>CYTOKINESIS<em>, or the division of the cytoplasm into two daughter </em><em>cells.</em>
