Answer : The change in boiling point is, 
Explanation :
Formula used :

where,
= change in boiling point = ?
i = Van't Hoff factor = 3 (for MgI₂ electrolyte)
= boiling point constant for water = 
m = molality = 0.615 m
Now put all the given values in this formula, we get


Therefore, the change in boiling point is, 
Answer:
The answer is

Explanation:
The energy of a quantum of light can be found by using the formula
<h3>E = hf</h3>
where
E is the energy
f is the frequency
h is the Planck's constant which is
6.626 × 10-³⁴ Js
From the question
f = 4.31 × 10¹⁴ Hz
We have
E = 4.31 × 10¹⁴ × 6.626 × 10-³⁴
We have the final answer as

Hope this helps you
The answer to this question is C: the ability to memorize
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Explanation:
Sol. 450 ml there is LiCl 200 g
Sol. 1000 ml there is LiCl 200/450×1000
= 444.44 g
Molar = g/molar mass = 444.44/42.394 = 10.48 M
Answer 1
The sample will dissolve in more than 1 minute.
Explanation :-
Generally Solubility and rate of solubility of substances increase with the increase in temperature. So lower the temperature less fast will it dissolve in the same amount of water.
Since at 50 C it takes 1 minute to dissolve, at 20 C which is lower temperature it will take more time to dissolve.
Answer 2
Transition metals
Explanation:-
Hardness depends on the extent of metallic bonding for metals. More the number of electrons more the metallic bonding.
Alkali metals with just 1 valence electron have weak metallic bonding. Alkaline earth metals have just 2 valence electrons. Transition elements has more electrons in penultimate shell and valence shell than lanthanides. Transition metals with most metallic bonding are the hardest