Answer:
16
Explanation:
Group two elements are alkaline earth metal.
All these have two valance electrons. In order to achieve noble gas configuration it loses its two valance and get complete octet.
Reaction with group 16.
Reaction with oxygen,
They react with oxygen and form oxide.
2Ba + O₂ → 2BaO
2Mg + O₂ → 2MgO
2Ca + O₂ → 2CaO
this oxide form hydroxide when react with water,
BaO + H₂O → Ba(OH)₂
MgO + H₂O → Mg(OH)₂
CaO + H₂O → Ca(OH)₂
With sulfur,
Mg + S → MgS
Ca + S → CaS
Ba + S → BaS
Use the formula E=mc^2
energy given=<span>8.1 x 10^16 joules
</span>speed of <span>light = 3.00 × 10^8 m/s
</span>
plug in the values we'll get mass=<span>9.0 x 10-1 kg</span>
<h2>Answer:</h2>
He is right that the energy of vaporization of 47 g of water s 106222 j.
<h3>Explanation:</h3>
Enthalpy of vaporization or heat of vaporization is the amount of energy which is used to transform one mole of liquid into gas.
In case of water it is 40.65 KJ/mol. And 18 g of water is equal to one mole.
It means for vaporizing 18 g, 40.65 kJ energy is needed.
So for energy 47 g of water = 47/18 * 40.65 = 106.1 KJ
Hence the student is right about the energy of vaporization of 47 g of water.
Yes, they are right.Very good hand writing! You did a very great job on showing your work.