<span>There are 34 hydrogen atoms.
</span>
Answer:
228
Explanation:
alpha decay is removing alpha particle 
2 number of protons, 4 mass number = 2 protons + 2 neutrons
We have
90 protons and 142 neutrons
<u> - 2 protons - 2 neutrons</u>
88 protons 140 neutrons
Mass number of new (daughter) atom = 88 +140 = 228
When Br2 and NaF are mixed, no reaction would occur since Br cannot replace F in NaF which gives NaBr + F₂ as products. Hence, Fluorine is more reactive than Bromine. Hence, Br can't replace F.
<u>Explanation</u>:
- When two reactants Br2 and NaF are mixed, no reaction takes place since Br cannot replace F in NaF. By seeing the periodic table, the positions of the halogens in the periodic table, bromine is located way below fluorine.
- Bromine will not have sufficient energy to replace fluorine and so it will not have energy which is sufficient to join because of low reactivity. Among these fluorine represents the most reactive element among halogens.
- Some of you may think it is a single replacement reaction that gives NaBr + F₂ as products. But, according to the halogen reactivity, it decreases from top to down of the group. F is placed above Br. Hence, Fluorine is more reactive than Bromine. Hence, Br can't replace F.
Answer: In this case, you can estimate that the solubility of potassium nitrate in water at
60
∘
C
is equal to about
solubility
≈
110 g / 100 mL water
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
This tells you that a saturated solution of potassium nitrate will hold about
110 g
of dissolved salt, i.e. of dissociated salt, per
100 mL
of water at
60
∘
C
.
