Explanation:
The conversion of the liquid to the vapor below boiling temperature of liquid is called evaporation.
Each molecule in liquid phase is attracted to other molecules in liquid by the intermolcular forces of attraction. When the process of evaporation starts, the molecules has to change the phase from the liquid to vapor for which they have to break all these interaction so that they can escape. The molecules with sufficient energy to do so only can do this. These molecules with high energy leave and remaining molecules are ones which did not have the enough energy to evaporate. Thus, average kinetic energy of molecules in liquid left behind is lower than it was before. <u>So, evaporation is a cooling process because heat of the molecules was used up for breaking hotter molecules out into gas phase and the left ones are cooled.
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<u>Answer:</u> The correct answer is d-block.
<u>Explanation:</u>
Chromium is the 24th element of the periodic table. It belongs to period 4 and Group 6 of the periodic table.
The number of electrons present in this element are 24 because number of electrons is equal to the atomic number of the element.
Electronic configuration of this element is: ![[Ar]4s^23d^4](https://tex.z-dn.net/?f=%5BAr%5D4s%5E23d%5E4)
As, the last electron is entering the d-orbital. Hence, this element belongs to d-block of the periodic table.
Answer:
165 of CO₂.
Explanation:
In the reaction:
Na2CO3 + 2HCl → 2NaCl + CO2 + H2O
2 moles of HCl reacts producing 1 mole o CO₂
If 7.5 moles of HCl reacts, moles of CO₂ produced are:
7.5 moles of HCl ₓ ( 1 mol CO₂ / 2 mol HCl) = 3.75 mol CO₂. As molar mass of CO₂ is 44g/mol, mass of CO₂ is:
3.75 mol CO₂ ₓ (44g / 1mol) = <em>165 of CO₂ </em>
Answer:
B
Explanation:
If the student needs one gram but so far only has 0.37 grams, then the amount they need is the difference between what they need and how much they already have. 1-0.37=0.63 grams.
...which isn't actually an option because none of them have decimal points but I would say it is B anyway because it is the equivalent ratio and maybe there was a typo.
Hope this helped!
