Answer:
Sirius B is primarily made out of a carbon-oxygen mixture that was generated by helium fusion in the progenitor star. The outer atmosphere is now almost pure hydrogen, the element with the lowest mass.
Explanation:
The mass of piece of sterling silver jewelry is 33.24 g. It contains 92.5% silver Ag by mass. Since, sterling silver is an alloy of Ag-Cu thus, percentage of Cu will be:
% Cu=100-92.5=7.5%
Thus, mass of copper will be:
Molar mass of Cu is 63.546 g/mol, thus, number of moles of Cu can be calculated as follows:
Here, m is mass and M is molar mass.
Putting the values,
Now, in 1 mole of Cu there are 
thus, in 0.03923 mol, number of Cu atoms will be:
Thus, number of atoms of Cu will be
.
On the earth there is the top layer dirt then loam comes next
Answer:
1. The dye that absorbs at 530 nm.
Explanation:
The dye will absorb light to promote the transition of an electron from the HOMO to the LUMO orbital.
The higher the gap, the higher the energy of transition. The energy can be calculated by E = hc/λ, in which h and c are constants and λ is the wavelength.
The equation shows that the higher the energy, the higher the gap and the lower the wavelength.
Therefore, the dye with absorption at 530 nm has the higher HOMO-LUMO gap.
Answer is: the % ionization of hypochlorous acid is 0.14.
Balanced chemical
reaction (dissociation) of an aqueous solution of hypochlorous acid:
HClO(aq) ⇄ H⁺(aq) + ClO⁻(aq).
Ka = [H⁺] · [ClO⁻] / [HClO].
[H⁺] is equilibrium concentration of hydrogen cations or protons.
[ClO⁻] is equilibrium concentration of hypochlorite anions.
[HClO]
is equilibrium concentration of hypochlorous acid.
Ka is the acid
dissociation constant.
Ka(HClO) = 3.0·10⁻⁸.
c(HClO) = 0.015 M.
Ka(HClO) = α² · c(HClO).
α = √(3.0·10⁻⁸ ÷ 0.015).
α = 0.0014 · 100% = 0.14%.
