In a physical change the form changes or the state of the matter. For instance water can freeze and water can melt, but it is still water.
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Answer:

Explanation:
The formula for the heat released is
q = mCΔT
Data:
m = 28.9 g
C = 0.385 J·°C⁻¹g⁻¹
T₁ = 1083 °C
T₂ = 25.0 °C
Calculations:
(a)Temperature change
ΔT = T₂ - T₁ = 25.0 - 1083 = -1058 °C
(b) Heat released
q = 28.9 × 0.385 × (-1058) = -11 800 J = -11.8 kJ
The negative sign shows that energy is released, so the copper has released
of energy.
This problem is asking for the theoretical effective nuclear charge for sodium and a reason behind its difference with the actual one. At the end, the answers are 1+ and because the 3s¹ electron has a small probability of being closer to the nucleus.
<h3>Effective nuclear charges</h3>
In chemistry, the effective nuclear charge is defined as the net positive charge valence electrons experience. In addition, one can approximate it with the equation:
Zeff = Z – S
Where Z is the atomic number or number of electrons and S the core electrons.
In such a way, since sodium has 11 electrons and 10 core electrons due to its electron configuration (1s²2s²2p⁶3s¹), one concludes its effective nuclear charge is:
Zeff = 11 - 10 = +1
On the other hand, since the actual effective nuclear charge has a value of about 2.667, one concludes this difference is due to the fact that the 3s¹ electron has a small tendency of being closer to the nucleus and therefore, there is a likelihood that this electron undergoes a greater attraction in comparison to the proposed in the theoretical model.
Learn more about effective nuclear charges: brainly.com/question/6965287
The answer would be C. Movement of crustal plates.
Answer: 1
Explanation:
a mole is always equal to 6.02 x 10^23 molecules, or in this case, atoms
so to find the number of moles, divide total atoms / 6.02 x 10^23
total atoms = 6.02 x 10^23
6.02 x 10^23 / 6.02 x 10^23 = 1
so 1 mole