The answer to this would be promptly A.
Answer:
The correct answer is option false.
Explanation:
Molality of the solution defined as moles of substance present in 1 kilogram of solvent.
Moles = 

Mass of percent (w/w%) of the solution is defined as amount of solute present in 100 grams of solution.

So, if want to inter-convert molality into mass percent we can do that without knowing density of solution.
Mass of solution = Mass of solute + Mass of solvent
Answer:
(a) ₁₉K: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
(b) ₁₀Ne: 1s² 2s² 2p⁶
---
(a) 3
(b) 6
(c) 7
Explanation:
We can state the ground-state electron configuration for each element following Aufbau's principle.
(a) ₁₉K: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
(b) ₁₀Ne: 1s² 2s² 2p⁶
Second part
(a) Al belongs to Group 13 in the Periodic Table. It has 13-10=3 electrons in the valence shell.
(b) O belongs to Group 16 in the Periodic Table. It has 16-10=6 electrons in the valence shell.
(c) F belongs to Group 17 in the Periodic Table. It has 17-10=7 electrons in the valence shell.
Answer: Option 1, 4 and 5 describe acids accurately.
Explanation:
Option 1: Acids have a sour taste because of the concentration of
ion.
Option 2: They are corrosive in nature, that is they are not at all gentle with the skin and fabric as some acids intend to burn skin such as
is a strong acid which can burn skin as well as fabric.
Option 3: Acids need electrons to release
ions and non-metals do not donate electrons hence, there is no reaction between a non-metal and an acid.
Option 4: All acids do contain hydrogen. They dissociate in the presence of water to produce
ions.

Option 5: Acids do conduct electricity that is they carry electrical charges. This was explained by Arrhenius. He said that the acids dissociate into
ions, when it is dissolved in water. These ions hence acts as charge carriers in water.
AS given that we have started with a solid powder on a glass plate which appears to be blackish yellow, on passing magnet the black particles separated.
so the black particles are magentic in nature. however the yellow portion of powder is not magnetic or diamagnetic
so its clear that we are able to separate the black and yellow portions by simple physical methods.
If we are able to separate any two substances by simple physical methods then it means that the powder is a mixture and not a compount