Answer:
Approximately 
.
Explanation:
This question can be solved using Hess's Law.
Start by considering: how can the first three reactions (with known 
values) be combined to produce the reaction 
?
Here's one possible combination:
- Include the first reaction once, without inverting.
- Invert the second reaction and include it once.
- Include the third reaction after multiplying all its coefficients by two.
In other words, if 
, 
, and 
denote the three reactions with know values, respectively, then 
will give the required reaction .
By Hess's Law, the value of the reaction will thus be:
.
Answer:
oooooooooooooooooh i dont know this one
Explanation:
im confuzzled
Answer: alkaline earth metals (group-IIA)
Explanation:
The element which donates the electron is known as electropositive element and forms a positively charged ion called as cation. The element which accepts the electrons is known as electronegative element and forms a negatively charged ion called as anion.
Alkaline earth metals donate 2 valence electrons to acquire noble gas configuration.
For example: Berrylium is the first alkaline earth metal with atomic number of 4 and thus has 4 electrons
Electronic configuration of berrylium:
![[Be]:4:1s^22s^2](https://tex.z-dn.net/?f=%5BBe%5D%3A4%3A1s%5E22s%5E2)
Berrylium atom will loose two electrons to gain noble gas configuration and form berrylium cation with +2 charge.
![[Be^{2+}]:2:1s^2](https://tex.z-dn.net/?f=%5BBe%5E%7B2%2B%7D%5D%3A2%3A1s%5E2)
Thus Elements donate 2 electron to produce a cation with a 2+ charge are alkaline earth metals.
The temperature or the average kinetic energy of the molecules
