VSEPR notation gives a general formula for classifying chemical species based on the number of electron pairs around a central atom. However, not all species have the same molecules.
For example, carbon dioxide and surfer dioxide are both species, but one is linear and another one is bent.
<h3>Answer:</h3>
Br (Bromine)
<h3>Explanation:</h3>
Li and K,
As the electronegativity difference between Li and K is less than 1.7 therefore, ionic bond cannot form between these two metals.
Li and Fe,
The electronegativity difference is less than 1.7 so neither electron loss nor electron gaining will take place between these two metals. Therefore, there will be no ionic bond between them.
Li and Kr,
As Krypton is a noble gas and does not react due to complete octet hence the formation of KrLi is difficult. However, Krypton can make compounds like KrF₂ e.t.c. Therefore we can skip this option.
For Li and K,
E.N of Bromine = 2.96
E.N of Lithium = 0.98
________
E.N Difference 1.98 (Ionic)
This ionic compound is possible and is the correct option because ionic compounds are always made by metals and non metals and here the combination is perfect.
<h3>Conclusion:</h3>
Lithium (a metal) and form Ionic bond with Bromine (a non metal)
Answer:
Explanation:
Heat flow equation => q = m·c·ΔT
m = mass in grams = 10.00 grams
c = specific heat (a constant) = 0.900j/g·°C
ΔT = temperature change in °C = 50°C - 25°C = 25°C
q = (10.00g)(0.900j/g·°C)(25°C) = 225 joules absorbed*
*absorbed => endothermic process => need to show 'plus' energy change.
If the reactions were an exothermic process the problem would use terms like energy released, energy lost, energy given-up, etc... => would require using a 'negative' signage before the calculated energy value. So, the correct choice is the +225 joules value.
