It is an endothermic reaction, the chemicals (probably water and ammonium nitrate) require more energy to react therefore it absorbs heat from it's surrounding to power the reaction and thus lowering the surrounding temperature. <span />
Magic number is any number in electron shells that suggest stability. It corresponds to total number of electrons in filled electron shells.
If an electron is having magic number, then it forms stable bonds.
Explanation:
The magic numbers are 2,10,18,36,54, 86 and 126. This refers to the total number of electrons that an electron can have when it is completely filled.
Atomic nuclei which carries either of these nucleons have high binding energy as compared to others. Hence, they have high stability. Bonds in such elements are more strong.
Radioactive decay of such elements is very slow.
Eugene Winger coined the term "magic number".
Negatively-charged ions are anions, formed from nonmetallic elements like OXYGEN and sulfur.
Answer:
C
Explanation:
When the Kb is given, the Henderson-Hasselbalch equation can be used to calculate the pOH of a buffer solution:
pOH = pKb + log ([A⁻] / [HA]) = -log(Kb) + log ([BH+] / [B])
Here, moles can be used in place of the concentration since the pairs listed are both dissolved in 5L, which cancel due to the fraction in the logarithm.
a) pOH = -log(1.8 x 10⁻⁵) + log(1.5/1.0) = 4.92
pH = 14 - pOH = 14 - 4.92 = 9.08
b) pOH = -log(1.8 x 10⁻⁵) + log(1.0/1.5) = 4.57
pH = 14 - pOH = 14 - 4.57 = 9.43
c) pOH = -log(1.7 x 10⁻⁹) + log(1.5/1.0) = 8.95
pH = 14 - pOH = 14 - 8.95 = 5.05
d) pOH = -log(1.7 x 10⁻⁹) + log(1.0/1.5) = 8.59
pH = 14 - pOH = 14 - = 5.41
Answer:
A
Explanation:
The equation for this conversion is 
Mr is molar mass.
