The much of the sample that would remain unchanged after 140 seconds is 2.813 g
Explanation
Half life is time taken for the quantity to reduce to half its original value.
if the half life for Scandium is 35 sec, then the number of half life in 140 seconds
=140 sec/ 35 s = 4 half life
Therefore 45 g after first half life = 45 x1/2 =22.5 g
22.5 g after second half life = 22.5 x 1/2 =11.25 g
11.25 g after third half life = 11.25 x 1/2 = 5.625 g
5.625 after fourth half life = 5.625 x 1/2 = 2.813
therefore 2.813 g of Scandium 47 remains unchanged.
Answer: all of them duuuuuuuuuuuuuuuuuuuuuuuuuuuuu
Partial pressure=mole fraction×Pt
x=0.044÷44(maolarmass of CO2)×Pt
x=0.044÷(44)2×Pt
x=5×10^-4×Pt
x=5×10^-4×Pt
where Pt:1atm=760mmHg
xatm=750mmHg
750×1÷760=0.99
now;5×10^-4×099=4.95×10^-4.
Pt=4.95×10^-4
The correct option is COVALENT BONDS.
A Lewis acid is defined as a substance which accept a pair of electron while a Lewis base refers to a substance that donate an unshared pair of electrons to another chemical specie with which it shared the donated pair of electrons.
Lewis acid and Lewis base react together to form salt and water. This type of reaction is called neutralization reaction. The neutralization reaction of Lewis acid and Lewis base involves electron pairs transfer, thus, there is an increase in the number of covalent bonds during this reaction.
