Answer:
You may know the formula of calcium chloride (is:-CaCl2)
So.
CaCl2 ⇄ Ca-²+2Cl-¹
1mole⇄1mole+2moles
So from above ..
1mole CaCl2 produce 1mole Ca-² & 2 moles of Cl-².
For 2.5 moles we multiply the above chemical eq. With 2.5
2.5CaCl2⇄2.5Ca-²+5Cl-¹
So from 2.5 moles of CaCl2 we get 2.5 mole calcium ion and 5 moles chloride ion…
Explanation:
Explanation:
(1) When a proton is converted into neutron then the positron emission takes place as follows.
![^{1}_{1}p \rightarrow ^{1}_{0}n + ^{0}_{+1}e](https://tex.z-dn.net/?f=%5E%7B1%7D_%7B1%7Dp%20%5Crightarrow%20%5E%7B1%7D_%7B0%7Dn%20%2B%20%5E%7B0%7D_%7B%2B1%7De)
A positron is represented by the symbol
. Therefore, when a positron emission occurs then the resultant nuclei atomic number decreases by a unit mass.
General equation representing positron emission is as follows.
![^{M}_{Z}A \rightarrow ^{M}_{Z-1}B + ^{0}_{+1}e](https://tex.z-dn.net/?f=%5E%7BM%7D_%7BZ%7DA%20%5Crightarrow%20%5E%7BM%7D_%7BZ-1%7DB%20%2B%20%5E%7B0%7D_%7B%2B1%7De)
Hence, Fluorine-18 decays by positron emission as follows.
![^{18}_{9}F \rightarrow ^{18}_{8}O + ^{0}_{+1}e](https://tex.z-dn.net/?f=%5E%7B18%7D_%7B9%7DF%20%5Crightarrow%20%5E%7B18%7D_%7B8%7DO%20%2B%20%5E%7B0%7D_%7B%2B1%7De)
Therefore, when 18F undergoes positron emission, the product nucleus is,
.
(2) Expression for the half-life of a
isotope is as follows.
![t_{\frac{1}{2}} = \frac{0.693}{\lambda}](https://tex.z-dn.net/?f=t_%7B%5Cfrac%7B1%7D%7B2%7D%7D%20%3D%20%5Cfrac%7B0.693%7D%7B%5Clambda%7D)
Initial activity, (
) = 4.00 millicuries
Activity after 95% = ![4.00 - 4.00 \times \frac{95}{100}](https://tex.z-dn.net/?f=4.00%20-%204.00%20%5Ctimes%20%5Cfrac%7B95%7D%7B100%7D)
= 0.20 millicuries
![\lambda = \frac{2.303}{t} log \frac{[N]_{o}}{[N]_{t}}](https://tex.z-dn.net/?f=%5Clambda%20%3D%20%5Cfrac%7B2.303%7D%7Bt%7D%20log%20%5Cfrac%7B%5BN%5D_%7Bo%7D%7D%7B%5BN%5D_%7Bt%7D%7D)
t = 7.912 hrs
Thus, we can conclude that it will take 7.91 hrs for 95% of the 18F to decay.
Answer:
Here's what I get.
Explanation:
(a) F, Cl, Br, and I are called halogens (salt formers)
(i) They are placed in Group 17, the Group just before Group 18 (the noble gases), because they need just one more valence electron to get a noble gas electron configuration.
(ii) At room temperature, iodine is a lustrous, purple-black solid that melts to form a deep violet liquid at 114 °C.
Answer:
spring tide
Explanation:
when both the sun and moon aligned th affect of each is added together producing higher than normal tides called SPRING TIDES
<span>MgO + HCl = MgCl2* + H2*O
To balance an equation, you have to have both the reactants and products side equal.
Mg = 1 Mg = 1
H = 1 H = 2
Cl = 1 Cl = 2
MgO + 2HCl = MgCl2 + H2*O
We added the coefficient 2, so they could balance. </span>