Answer:
Without dark matter galaxies would loose an extreme amount of gas required to create stars.
Without dark matter the universe wont have as many galaxies clumped together forming larger versions of those galaxies. This would cause a change in the structure of the "skeleton" of the web.
(Hope this can help, I didn't do exactly as it is said to because that is your job)
:)
Explanation:
Forbes gives somewhat of an explanation if you are curious.
(Ethan Siegal, "The Universe Would Be Very Different Without Dark Matter", Forbes)
Answer:
2.4 ×10^24 molecules of the herbicide.
Explanation:
We must first obtain the molar mass of the compound as follows;
C3H8NO5P= [3(12) + 8(1) + 14 +5(16) +31] = [36 + 8 + 14 + 80 + 31]= 169 gmol-1
We know that one mole of a compound contains the Avogadro's number of molecules.
Hence;
169 g of the herbicide contains 6.02×10^23 molecules
Therefore 669.1 g of the herbicide contains 669.1 × 6.02×10^23/ 169 = 2.4 ×10^24 molecules of the herbicide.
The ionic character of any compound depend on the lattice energy as well as the electronegativity of element present in that compound.
More would be the lattice energy more would be ionic nature of that compound.
The lattice energy of any compound is inversely proportional to the ionic radii cation and anion.
In given case the ionic radii of oxide in both oxides would be equal therefore the lattice energy only depend on the ionic radii of cation.
As the radii of Magnesium less then radii of lithium therefore lattice energy of Magnesium oxide would be more than lithium oxide.
Hence, MgO would be more ionic in nature than 
Answer:
ν = 7.04 × 10¹³ s⁻¹
λ = 426 nm
It falls in the visible range
Explanation:
The relation between the energy of the radiation and its frequency is given by Planck-Einstein equation:
E = h × ν
where,
E is the energy
h is the Planck constant (6.63 × 10⁻³⁴ J.s)
ν is the frequency
Then, we can find frequency,

Frequency and wavelength are related through the following equation:
c = λ × ν
where,
c is the speed of light (3.00 × 10⁸ m/s)
λ is the wavelength

A 426 nm wavelength falls in the visible range (≈380-740 nm)
Answer:

Explanation:
Hello,
In this case, the undergoing chemical reaction is:

Next, we identify the limiting reactant by computing the moles of magnesium oxide yielded by 3.86 g of magnesium and 155 mL of oxygen at the given conditions via their 2:1:2 mole ratios and the ideal gas equation:

It means that the limiting reactant is the oxygen as it yields the smallest amount of magnesium oxide. Next, we compute the mass of magnesium consumed the oxygen only:

Thus, the mass in excess is:

Regards!