Answer:
Helium is the second element on the periodic table. It is located in period 1 and group 18 or 8A on the righthand side of the table. This group contains the noble gases, which are the most chemically inert elements on the periodic table. Each He atom has two protons and usually two neutrons and two electrons.
Explanation:
thoughtco.com
Empirical formula is the simplest ratio of components making up a compound.
The percentage composition of each element has been given
therefore the mass present of each element in 100 g of compound is
B N H
mass 40.28 g 52.20 g 7.53 g
number of moles
40.28 g / 11 g/mol 52.20 g / 14 g/mol 7.53 g / 1 g/mol
= 3.662 mol = 3.729 mol = 7.53 mol
divide the number of moles by the least number of moles, that is 3.662
3.662 / 3.662 3.729 / 3.662 7.53 / 3.662
= 1.000 = 1.018 = 2.056
the ratio of the elements after rounding off to the nearest whole number is
B : N : H = 1 : 1 : 2
therefore empirical formula for the compound is B₁N₁H₂
that can be written as BNH₂
Answer:
A) CH3CH2CH2CH2CH2CH2OH
Explanation:
For this question, we have the following answer options:
A) CH3CH2CH2CH2CH2CH2OH
B) (CH3CH2)2CH(OH)CH2CH3
C) (CH3CH2)2CHOHCH3
D) (CH3CH2)3COH
E) (CH3CH2)2C(CH3)OH
We have to remember the<u> reaction mechanism</u> of the substitution reaction with 
. <em>The idea is to generate a better leaving group in order to add a "Br" atom.</em>
The attacks the "OH" generation new a bond to P (O-P bonds are very strong), due to this new bond we will have a better leaving group that can remove the oxygen an allow the attack of the Br atom to generating a new C-Br bond. This is made by an <u>Sn2 reaction</u>. Therefore we will have a faster reaction with <u>primary substrates</u>. In this case, the only primary substrate is molecule A. So, <em>"CH3CH2CH2CH2CH2CH2OH"</em> will react faster.
See figure 1
I hope it helps!
The question is incomplete as it does not have the options which are:
(1) receiving antibiotic injections after surgery
(2) choosing a well-balanced diet and following it throughout life
(3) being vaccinated against chicken pox
(4) receiving hormones contained in mothers milk while nursing
Answer:
Being vaccinated against chicken pox
Explanation:
Vaccination is the procedure of giving the disease-causing germs which could be virus and bacteria in their dead or weakened state, some toxin, some proteins or some other molecules called a vaccine.
The benefit of providing vaccination is that the provided pathogen acts as an antigen and triggers the proactive immune response against the pathogen which helps in eradicating the main pathogen that has invaded the body. The vaccination is used to treat the disease like chickenpox, measles, tetanus and many others.
Thus, the selected option is correct.
