Answer:
A is the correct answer.
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
For example in case of Helium:
The 1st one diagram shows that arrow is pointing with in nucleus. The helium nucleus contain two protons and two neutrons. Thus maximum mass is present with in nucleus. while two electrons are revolve around the nucleus and mass of electron is negligible.
Answer:
Alkylenes: any of the series of unsaturated hydrocarbons containing a triple bond, including acetylene.
alkanes: Alkanes are organic compounds that consist entirely of single-bonded carbon and hydrogen atoms and lack any other functional groups. Alkanes have the general formula CnH2n+2 and can be subdivided into the following three groups: the linear straight-chain alkanes, branched alkanes, and cycloalkanes.
Explanation:
The balanced chemical reaction is:
<span>Mg(OH)2 + 2HCl
--> MgCl2 + 2H2O</span>
So we can see that 2 moles of HCl reacts for every 1 mole
of Mg(OH)2.
moles HCl left = 0.125 M * 0.150 L – (0.125 M * 0.040 L) *
2
moles HCl left = 0.00875 mol
So the concentration of H+ ion is:
[H+] = 0.00875 mol / (0.150 L + 0.040 L)
[H+] = 0.046 M
So the pH is:
pH = - log 0.046
<span>pH = 1.34</span>
The distance between the scattering planes in the crystal is d = 0.95 A°
<u>Explanation</u>:
The Bragg's equation is given by
2d sinθ = nλ
where,
d is the distance between the scattering planes in the crystal.
θ is the angle of diffraction.
n is the order of diffraction.
λ is the wavelength of X rays.
Given λ = 0.17 nm = 1.7 A°, angle = 62.5
2 
d sin(62.5) = 1 1.7 A°
d = 0.95 A°
The distance between the scattering planes in the crystal is d = 0.95 A°
