Answer:
C. representative elements.
Explanation:
Families 1 - 2 and 13 - 18 are called representative elements or often times, main group elements.
- Elements on the periodic table belongs to four blocks which are s, p, d and f blocks.
- Those in the s and p-blocks are the main group elements also called representative elements.
- Their outer-shell are not completely filled with electrons but their inner shell is completely filled.
It gains or loses electrons to become like the Noble gases having 8 valence electrons to become the most stable.
Yes, the law of thermodynamics, or Law of Conservation of Energy
To solve this problem, we must assume ideal gas behaviour so
that we can use Graham’s law:
vA / vB = sqrt (MW_B / MW_A)
where,
<span>vA = speed of diffusion of A (HBR)</span>
vB = speed of diffusion of B (unknown)
MW_B = molecular weight of B (unkown)
MW_A = molar weight of HBr = 80.91 amu
We know from the given that:
vA / vB = 1 / 1.49
So,
1/1.49 = sqrt (MW_B / 80.91)
MW_B = 36.44 g/mol
Since this unknown is also hydrogen halide, therefore this
must be in the form of HX.
HX = 36.44 g/mol , therefore:
x = 35.44 g/mol
From the Periodic Table, Chlorine (Cl) has a molar mass of
35.44 g/mol. Therefore the hydrogen halide is:
HCl