You can not see between opaque materials because light cannot pass through them.
Answer:
When the two atoms move towards each other a compound is formed by sharing electron pairs supplied by each of the atoms to enable them have the stable 8 (octet) valency electrons in their outermost shell
Explanation:
The electronic configuration of the given element can be written as follows;
1s²2s²2p⁴
The given electronic configuration is equivalent to that of oxygen, therefore, we have;
The number of electrons in the valence shell = 2 + 4 = 6 electrons
Therefore, each atom requires 2 electrons to complete its 8 (octet) electrons in the outermost shell
When the two atoms move towards each other, they react and combine to form a compound by sharing 4 electrons, 2 from each atom, such that each atom can have an extra 2 electrons in its outermost orbit in the newly formed compound and the stable octet configuration is attained by each of the atoms in the newly formed compound.
1. At constant tempaerature and pressure, 3 tablets produce 600cm^3 of gas
Thus calculating for 1 tablet that produces 600 / 3 = 200 cm^3
So now two tablets produce 200 x 2 = 400 cm^3
2. We have the equation PV = nRT, n being the number of moles
Pressure P = 1,000 kPa
Volume V = 3 L
R = 8.31 L kPa/mol-K
Temperature T = 298 K
n = PV / RT = (1000 x 3) / (8.31 x 298) = 3000 / 2476.38 = 1.21 moles
Number of moles = 1.21 moles.
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KH₂PO₄ hydrolyzes as;
H₂PO₄⁻ + H₂O ↔ H₃PO₄ + OH⁻
Let x amount of H₂PO₄⁻ has reacted with water then,
Kb₁ = [H₃PO₄][OH⁻] / [H₂PO₄⁻]
[H₂PO₄⁻] = 0.8-x M
Kb₁ = x² / (0.8 - x)
Given Ka₁ = 7.5 x 10⁻³
so Kb₁ = 1 x 10⁻¹⁴ / (7.5 x 10⁻³) = 1.33 x 10⁻¹²
From this information:
1.33 x 10⁻¹² = x² / 0.8
x = [OH⁻] = 1.03 x 10⁻⁶ M
pOH = - log (1.03 x 10⁻⁶) = 5.99
pH = 14 - pOH = 14 - 5.99 = 8.01
