The asthenosphere is directly below the lithosphere so the answer to your question is the asthenosphere, because the outer core is towards the center of Earth.
Answer:
I think the answer is A - they used X-ray analysis.
Explanation:
Formula units in 450 g of
is 1.93 × 10²⁴ formula units.
<u>Explanation:</u>
First we have to find the number of moles in the given mass by dividing the mass by its molar mass as,

Now, we have to multiply the number of moles of Na₂SO₄ by the Avogadro's number, 6.022 × 10²³ formula units/mol, so we will get the number of formula units present in the given mass of the compound.
3.2 mol × 6.022 × 10²³ = 1.93 × 10²⁴ formula units.
So, 1.93 × 10²⁴ formula units is present in 450g of Na₂SO₄.
Answer: 9.27 g of Na
Explanation:Please see attachment for explanation
Answer: 14.1g
Explanation:
Given that,
number of moles of SiO2 = 0.235 moles
Mass in grams = Z (let unknown value be Z)
Molar mass of SiO2 = ?
To get the molar mass of SiO2, use the atomic mass
Silicon = 28g;
Oxygen = 16g
i.e Molar mass of SiO2 = 28g + (16g x 2)
= 28g + 32g
= 60g/mol
Now, apply the formula
Number of moles = Mass / molar mass
0.235 moles = Z / 60g/mol
Z = 0.235 moles x 60g/mol
Z = 14.1 g
Thus, the mass of SiO2 is 14.1 grams.